液相合成中纳米材料的形貌、尺寸和晶面结构对性能的影响

Layered intercalating V2O5 (vanadium pentoxide) is a durable battery-type electrode material exploited in supercapacitors. The advancement of V2O5 nanomaterials synthesized from non-aqueous organic solvents holds significant potential for energy storage applications. Liquid-phase synthesis of orthorhombic V2O5 cathode material corroborated its compatibility with quartet glycols and allowed examination of their explicit roles in faradic charge storage efficacy. V2O5 was found to be an intercalative material in all the quartet glycols. The crystalline, rod-like morphology and monodisperse V2O5 electrode were ascribed to the effects of ethylene, diethylene, triethylene, and tetraethylene glycols. Notable differences were observed in the electrochemical analysis of the prepared V2O5 (EV, DV, TV, and TTV). In a three-electrode cell setup, the DV electrode demonstrated a superior specific capacity of 460.2 C/g at a current density of 1 A/g. From the Trasatti analysis, the DV electrode exhibited 961.53 C/g of total capacitance, comprising a diffusion-controlled contribution of 898.19 C/g and a surface-controlled contribution of 63.34 C/g. The aqueous asymmetric device DV//AC exhibited a maximum energy density of 65.72 Wh/kg at a power density of 1199.97 W/kg. The glycol-derived electrodes were anticipated to bepromising materials for supercapacitors and have the potential to meet electrochemical energy needs.

To solve the problem of liquid-phase synthesis of nano-ZnO, a photocatalytic performance study was proposed. In this study, the microwave homogeneous precipitation method was used to add different types and amounts of surfactants. The synthesis of nano-zinc oxide was controlled by changing the reaction system conditions. The photocatalytic properties of nano-zinc oxide for degrading three water-soluble dyes were preliminarily studied and discussed. The results show that the photocatalytic performance of nano-ZnO is closely related to its size, morphology, specific surface area, and even crystallographic direction.

The article focuses on the problems of development of electrochemical devices. The effect of a synthesis method and fabrication technology on the electrochemical performance of a MnO2-based electrode is discussed.

In this study, a facile and scalable method for synthesizing MoSe2 nanomaterial via a sonication-assisted liquid-phase exfoliation method is proposed. This study shows the successful synthesis of few-layered MoSe2 in various solvents including DI water, ethanol, N-Methyl-2-pyrrolidone (NMP), Dimethylformamide (DMF) and Dimethylsulfoxide (DMSO). The exfoliated nanosheets have remarkably different properties than bulk MoSe2 which were studied using Field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and UV–Vis spectroscopy to investigate their morphology, functional groups, structure and optical properties, respectively. The mean values of the number of layers from an optical extinction spectrum based on the effect of edge and quantum confinement were also calculated. Moreover, the exfoliated material using this method has potential application in energy storage as demonstrated by the electrochemical performance of the bulk and exfoliated materials.• Successful synthesis of the few-layer MoSe2 from bulk MoSe2 using liquid phase exfoliation method in various solvents• The investigation of the effect of solvent on the number of layers and optical properties of MoSe2

Recently, C60 has emerged as a promising anode material for Li-ion batteries, attracting significant interest due to its excellent lithium storage capacity. The electrochemical performance of C60 as an anode is largely dependent on its internal crystal structure, which is significantly influenced by the synthesis method and corresponding conditions. However, there have been few reports on how the synthesis process affects the crystal structure and Li+ storage capacity of C60. This study used the liquid-liquid interface precipitation method and a low-temperature annealing process to fabricate one-dimensional C60 nanorods (NRs). We thoroughly investigated synthesis conditions, including the growth time, drying temperature, annealing time, and annealing atmosphere. The results demonstrate that these synthesis conditions directly impact the morphology, phase transition, and electrochemical efficiency of pure C60 NRs. Remarkably, the hexagonal close-packed structural C60 NRs-6012h, in a metastable form, exhibits a reversible Li+ storage capacity as an anode material in Li-ion batteries. Furthermore, the face-centered cubic C60 NRs-603001h electrode shows significantly enhanced rate performance and long-cycle stability. A discharge-specific capacity of 603 mAh g-1 was maintained after 2000 cycles at a current density of 2 A g-1. This study elucidates the effect of synthesis conditions on C60 crystals, offering an effective strategy for preparing high-performance C60 anode materials.

Aqueous zinc-ion batteries (ZIBs) provide a safer and cost-effective energy storage solution by utilizing nonflammable water-based electrolytes. Although many research efforts are focused on optimizing zinc anode materials, developing suitable cathode materials is still challenging. In this study, one-dimensional, mixed-phase MnO2 nanorods are synthesized using ionic liquid (IL). Here, the IL acts as a structure-directing agent that modifies MnO2 morphology and introduces mixed phases, as confirmed by morphological, structural, and X-ray photoelectron spectroscopy (XPS) studies. The MnO2 nanorods developed by this method are utilized as a cathode material for ZIB application in the coin-cell configuration. As expected, Zn//MnO2 nanorods show a significant increase in their capacity to 347 Wh kg-1 at 100 mA g-1, which is better than bare MnO2 nanowires (207.1 Wh kg-1) synthesized by the chemical precipitation method. The battery is highly rechargeable and maintains good retention of 86% of the initial capacity and 99% Coulombic efficiency after 800 cycles at 1000 mA g-1. The ex situ XPS, X-ray diffraction, and in-depth electrochemical analysis confirm that MnO6 octahedra experience insertion/extraction of Zn2+ with high reversibility. This study suggests the potential use of MnO2 nanorods to develop high-performance and durable battery electrode materials suitable for large-scale applications.

Sodium ion batteries represent a sustainable alternative to Li-ion technologies. Challenges with material properties remain, however, particularly with regards the performance of anodes. We report a rapid, energy-efficient ionic liquid synthesis method for mixed phase Na2Ti3O7 and Na2Ti6O13 rods. This method is based on a novel phase-transfer route which produces pure functional materials via a dehydrated IL. The structure of the synthesised materials was characterised using powder X-ray diffraction, which confirms the formation of a mixed Na2Ti3O7 and Na2Ti6O13 phase, with majority Na2Ti3O7 phase, in contrast to previous synthesis methods. Scanning and transmission electron microscopy analysis reveals a rod morphology, with an average diameter and length of 87 nm ± 3 nm and 1.37 μm ± 0.07 μm, respectively. The initial discharge and charge capacity of Na2Ti3O7 nanorods were measured as 325.20 mA h g-1 and 149.07 mA h g-1, respectively, at 10 mA g-1 between 0.01-2.5 V. We attribute the enhanced performance to the higher weight fraction of Na2Ti3O7 phase vs. previous reports, demonstrating the potential of the ionic liquid method when applied to sodium titanate materials.

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Molybdenum complexes are versatile and efficient for liquid phase olefin epoxidation reactions. Rational design of catalysts is critical to achieve high atom efficiency during epoxidation processes. Although liquid phase epoxidation has been a popular topic for decades, three key issues, (a) rational control of morphology of molybdenum nanoparticles, (b) manipulating metal-support interaction and (c) altering electronic configuration at molybdenum center remains unsolved in this area. Therefore, in this paper, we have critically revised recent research progress on heterogeneous molybdenum catalysts for facile liquid phase olefin epoxidation in terms of catalyst synthesis, surface characterization, catalytic performance and structure-function relationship. Furthermore, plausible reaction mechanisms will be systematically discussed with the aim to provide insights into fundamental understanding on novel epoxidation chemistry.

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High-performance liquid chromatography is one of the most important analytical tools for the identification and separation of substances. The efficiency of this method is largely determined by the stationary phase of the columns. Although monodisperse mesoporous silica microspheres (MPSM) represent a commonly used material as stationary phase their tailored preparation remains challenging. Here we report on the synthesis of four MPSMs via the hard template method. Silica nanoparticles (SNPs) which form the silica network of the final MPSMs were generated in situ from tetraethyl orthosilicate (TEOS) in the presence of (3-aminopropyl) triethoxysilane (APTES) functionalized p(GMA-co-EDMA) as hard template. Methanol, ethanol, 2-propanol, and 1-butanol were applied as solvents to control the size of the SNPs in the hybrid beads (HB). After calcination, MPSMs with different sizes, morphology and pore properties were obtained and characterized by scanning electron microscopy, nitrogen adsorption and desorption measurements, thermogravimetric analysis, solid state NMR and DRIFT IR spectroscopy. Interestingly, the 29Si NMR spectra of the HBs show T and Q group species which suggests that there is no covalent linkage between the SNPs and the template. The MPSMs were functionalized with trimethoxy (octadecyl) silane and used as stationary phases in reversed-phase chromatography to separate a mixture of eleven different amino acids. The separation characteristics of the MPSMs strongly depend on their morphology and pore properties which are controlled by the solvent during the preparation of the MPSMs. Overall, the separation behavior of the best phases is comparable with those of commercially available columns. The phases even achieve faster separation of the amino acids without loss of quality.

Solid-liquid triboelectric nanogenerators (SL-TENGs) have attracted attention for use in water resource collection. However, traditional methods limit improvements in the surface energy density of the friction layer because of insufficient precision. This study used femtosecond laser technology to create three-dimensional bionic structures on polyvinylidene fluoride (PVDF) films. Zinc oxide (ZnO) seeds were embedded at specific locations via liquid-phase processing, and ZnO nanostructures were grown via hydrothermal synthesis. The morphological changes under different laser energies and frequencies were studied. The morphology under different processing parameters is characterized and analyzed. SL-TENGs fabricated with different parameters showed a 1.88-fold increase in the average peak open circuit voltage (VOC), presented 41.68 V, and a 10.52-fold increase in the average peak short circuit current (ISC), which reached 256.37 μA. The maximum power density was 3.28 W/m2, increasing by 7.45 times. The output performance was tested in different solutions, and SL-TENG was stable. This study introduced the regulation of the interface charge of ZnO-PVDF by femtosecond laser processing, enhanced the power generation effect of SL-TENG, and provided insights for future research.

Due to excellent conductivity, oxidation resistance and low electrochemical mobility of gold itself, gold conductor pastes were widely used in electronic technology. However, the application of gold conductor pastes was limited by irregular morphology, wide particle size distribution, and low tap density of gold powders, which were usually prepared by the traditional liquid-phase reduction method. In this work, gold powders with high crystallinity and average particle size of 1.5 μm were prepared by seed-mediated synthesis. The as-prepared gold powders exhibited uniform size distribution, regular morphology, and intact crystal structure. Owe to proper particle diameter and extraordinary dispersion, the tap density of gold powders was as high as 10.2 g/cm3. Gold particles were tightly packed during sintering of paste, promoting densification of sintered body and improving the conductivity of thick film circuit. Gold powders with high tap density and crystallinity served as a fundamental material for high-performance electronic pastes, which exhibited significant application potential in precision sensor electrodes.

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Shaping the morphology of 2D materials is essential for tuning their properties. This is especially true for MXenes, a class of 2D materials, as fine morphological control is the key to unlocking their potential. Here, Ti3C2Tx MXene is synthesized using carbon fibers as both the carbon source and template, creating a unique tubular morphology where the MXene layers align along the tube. The tubular Ti3C2Tx MXene and corresponding precursor MAX phase are synthesized by molten salts shielded synthesis method in air. Comprehensive characterization confirms that the MXene retains the tubular structure conferred by the carbon fiber. Preliminary electrochemical measurements as an anode material in lithium-ion batteries show an initial discharge capacity and good rate performance at a high current density, indicating potential for high-power applications. Furthermore, this tubular morphology opens new possibilities for MXenes in gas sensing, liquid filtration processes, and other applications that require fast diffusion. Choice of MAX phase precursor plays a significant role on the structure and properties of MXenes. Here, carbon fibers are used as the carbon source and template for the MAX phase, resulting in a Ti3C2Tx MXene with a tubular morphology.

Four types of flowerlike manganese dioxide in nano scale was synthesized via a liquid phase method in KMnO4-H2SO4 solution and Cu particles, wherein the effect of Cu particles was investigated in detail. The obtained manganese dioxide powder was characterized by XRD, SEM and TEM, and the supercapacity properties of MnO2 electrode materials were measured. The results showed that doping carbon black can benefit to better dispersion of copper particles, resulting in generated smaller size of Cu particles, and the morphology of MnO2 nanoparticles was dominated by that of Cu particles. The study of MnO2 synthesis by different sources of Cu particles showed that the size of MnO2 particles decreased significantly with freshly prepared fine copper powder compared with using commercial Cu powder, and the size of MnO2 particles can be further reduced to 120 nm by prepared Cu particles with smaller size. Therefore, it was suggested that the copper particles served as not only the reductant and but also the nuclei centre for the growth of MnO2 particles in synthesis process MnO2, and that is the reason how copper particles worked on the growth of flower-like MnO2 and electrochemical property. In the part of investigation for electrochemical property, the calculated results of b values indicated that the electrode materials have pseudo capacitance property, and the highest specific capacitance of 197.2 F g-1 at 2 mV s-1 and 148 F/g at 1 A/g were obtained for MCE electrode materials (MnO2 was synthesized with freshly prepared copper particles, where carbon black was used and dispersed in ethanol before preparation of Cu particles). The values of charge transfer resistance in all types of MnO2 materials electrodes were smaller than 0.08 Ω. The cycling retention of MCE material electrode is still kept as 93.8% after 1000 cycles.

Covellite-phase CuS and carrollite-phase CuCo2S4 nano- and microstructures were synthesized from tetrachloridometallate-based ionic liquid precursors using a novel, facile, and highly controllable hot-injection synthesis strategy. The synthesis parameters including reaction time and temperature were first optimized to produce CuS with a well-controlled and unique morphology, providing the best electrocatalytic activity toward the oxygen evolution reaction (OER). In an extension to this approach, the electrocatalytic activity was further improved by incorporating Co into the CuS synthesis method to yield CuCo2S4 microflowers. Both routes provide high microflower yields of >80 wt %. The CuCo2S4 microflowers exhibit a superior performance for the OER in alkaline medium compared to CuS. This is demonstrated by a lower onset potential (∼1.45 V vs RHE @10 mA/cm2), better durability, and higher turnover frequencies compared to bare CuS flowers or commercial Pt/C and IrO2 electrodes. Likely, this effect is associated with the presence of Co3+ sites on which a better adsorption of reactive species formed during the OER (e.g., OH, O, OOH, etc.) can be achieved, thus reducing the OER charge-transfer resistance, as indicated by X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy measurements.

V6O13 thin films were deposited on indium-doped tin oxide (ITO) conductive glass by a concise low-temperature liquid-phase deposition method and through heat treatment. The obtained films were directly used as electrodes without adding any other media. The results indicate that the film annealed at 400 °C exhibited an excellent cycling performance, which remained at 82.7% of capacity after 100 cycles. The film annealed at 400 °C with diffusion coefficients of 6.08 × 10−12 cm2·s−1 (Li+ insertion) and 5.46 × 10−12 cm2·s−1 (Li+ extraction) in the V6O13 film electrode. The high diffusion coefficients could be ascribed to the porous morphology composed of ultrathin nanosheets. Moreover, the film endured phase transitions during electrochemical cycling, the V6O13 partially transformed to Li0.6V1.67O3.67, Li3VO4, and VO2 with the insertion of Li+ into the lattice, and Li0.6V1.67O3.67, Li3VO4, and VO2 partially reversibly transformed backwards to V6O13 with the extraction of Li+ from the lattice. The phase transition can be attributed to the unique structure and morphology with enough active sites and ions diffusion channels during cycles. Such findings reveal a bright idea to prepare high-performance cathode materials for LIBs.

The catalytic hydrogenation of oxalic acid to glycolic acid (GA) and/or ethylene glycol (EG) has been identified as a promising route for producing value‐added chemicals and potential hydrogen carriers. GA serves as a precursor for plastics and cosmetics, while EG can function as a liquid organic hydrogen carrier. In this work, an eco‐friendly and scalable bottom‐up approach to fabricate a Ru‐based hydrogenation catalyst on θ‐alumina‐coated SiC foam is presented. Nitrogen doping of the MOF(Al)‐based template enhances the mechanochemical stability of the resulting alumina coating by significantly modifying its surface texture and morphology. This phase‐stabilization method enables higher OA conversion compared to γ‐alumina and yields nearly equimolar amounts of GA and EG under continuous‐flow conditions (120 °C, 50 bar). These findings demonstrate the potential of this synthesis approach for producing stabilized metal oxide phases with tailored morphologies that improve catalyst performance.

In the current work, a hierarchical nanocomposite based on MnO2 nanosheets attached to the C-Fe2O3 substrate (C-Fe2O3@MnO2) was introduced as a novel and efficient dispersive-μ-solid phase extraction sorbent. The well-prepared nanocomposite with unique morphology leading to higher surface area, high porosity, and excellent adsorptive capacity was used for preconcentration of antifungal drugs (ketoconazole, clotrimazole, and miconazole) from plasma and wastewater samples before analysis using high-performance liquid chromatography (HPLC-UV). The synthesized nanosorbent was characterized using XRD, FTIR, FE-SEM, BET/BJH, and EDX analysis. In the optimal condition, the limit of detection (LODs) and the limit of quantification (LOQs) were acquired as 1.5, 5.0 μg L-1 in the linear range of 5-500 μg L-1 in plasma samples and 0.3, 1.0 μg L-1 in the linear range of 1-150 μg L-1 in wastewater samples for all analytes. Furthermore, the relative standard deviations (RSD%) for the repeatability of the sorbent synthesis method and reusability of one sorbent were found to be 0.92, 1.23, 1.32 % and 2.43, 3.15, 4.28 % for ketoconazole, clotrimazole, and miconazole, respectively.

This study investigates the impact of graphene synthesis techniques, such as chemical exfoliation, Chemical Vapor Deposition (CVD) and Liquid Phase Exfoliation (LPE) on electrical conductivity. The objective is to understand how variations in synthesis methods influence the morphology of graphene and, consequently, its electrical characteristics. Description techniques are explored in detail to identify how each process affects the structure and electrical performance of graphene. The results indicate that chemical exfoliation introduces more damage to the graphene structure, generally its electrical conductivity, while the CVD method tends to produce graphene with greater uniformity and superior conductivity. LPE, on the other hand, offers a balance between quality and production efficiency, making it particularly promising for large-scale applications. The study provides valuable information for the selection of description methods based on specific graphene application requirements. The discoveries could facilitate the development of more efficient materials for advanced electronics, contributing to the optimization of industrial graphene production processes and promoting advanced advances in materials technology.

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The electromagnetic interference (EMI) shielding performance of Cu@Ag core-shell composites is significantly determined by the silver shell morphology and core-shell interface properties. However, in-situ regulation of these features remains challenging due to the unclear formation mechanism for the Ag shell. Herein, we present a ligand-regulated synthesis in which ammonia is employed to precisely control the growth of the silver shell during liquid-phase reduction. Ammonia forms stable [Ag(NH3)2]+ complexes with silver ions, which modify the deposition kinetics. Such a shift transitions the coating process from rapid, anisotropic plating to controlled, uniform growth. Consequently, the morphology of the silver shell evolves from plate-like to particle-like structure, accompanied by the formation of an Ag-Cu transition layer at the core-shell boundary. These structural refinements dramatically reduce the electrical resistivity from 6.42 Ω·cm to 6.37 × 10- 4 Ω·cm. And the optimized structure exhibits superior EMI shielding effectiveness of 85.4 dB across 5.85-18 GHz range, with a peak radiation suppression of 26.8 dB. Moreover, the SE is further enhanced to 101.7 dB through a stratified stacking strategy. This work demonstrates ligand regulation as an effective strategy for enhancing EMI shielding performance.

The P2-Na0.7MnO2.05 cathode material has long been constrained by phase transitions induced by the Jahn–Teller (J–T) effect during charge–discharge cycles, leading to suboptimal electrochemical performance. In this study, we employed a liquid phase co-precipitation method to incorporate Ti during the precursor Mn3O4 synthesis, followed by calcination to obtain Na0.7TixMn(1−x)O2.05 materials. We investigated the effects of Ti doping on the structure, morphology, Mn3+ concentration, and Na+ diffusion coefficients of Na0.7TixMn(1−x)O2.05. Our findings revealed that the 7% Ti-doped NTMO-007 sample exhibited reduced grain agglomeration and smaller particle sizes compared to the undoped sample, thereby enhancing the electrode–electrolyte contact area and electrochemical activity. Additionally, Ti doping increased the crystal cell volume of Na0.7MnO2.05 and broadened the Na+ transport channels, significantly enhancing the Na+ diffusion coefficient. At a 0.5 C rate, the NTMO-007 sample demonstrated a specific capacity of 143.3 mAh g−1 with an 81.8% capacity retention after 100 cycles, markedly outperforming the undoped NMO sample, which had a capacity retention of only 61.5%.

Cerium oxide (CeO2) exhibits application potential for the selective catalytic reduction of nitrogen oxides (NOx) with NH3 (NH3-SCR). The crystal facets and morphology of CeO2 have a vital impact on the catalytic performance of NH3-SCR. However, the precise influence mechanisms on SCR activity remain elusive. In this work, CeO2 is successfully synthesized with three distinct crystal facets and nine diverse morphologies. This investigation involves a comprehensive blend of theoretical analysis and experiments, to gain profound insights into the underlying mechanisms governing the SCR catalytic activity concerning morphology and crystal facets. By closely integrating density functional theory (DFT) calculations, Ab initio thermodynamic analysis, SCR catalytic activity experiments, and X-ray photoelectron spectroscopy experiments, it is discovered that the concentration of surface-active oxygen (O*) plays a pivotal role in determining the catalytic activity of CeO2 in SCR reactions, as opposed to factors like specific surface area or oxygen defect concentration. This experimental-theoretical joint study provides design principles of CeO2 catalysts for NO removal.

Spinel NiCo2O4 are excellent catalysts for complete methane oxidation. Nevertheless, the spinel structure is thermally unstable and its activity is negatively affected by humidity. Herein, we report crystal facet engineering...

Controlled growth of BiVO4 nanostructures along (121) and (040) crystal facets plays a crucial role in enhancing their catalytic performance. In this regard, the visible light active photocatalyst BiVO4 was synthesized concerning the effect of pH and surfactants by hydrothermal method. The morphology and size of BiVO4 are strongly dependent on the concentration of H+ and Bi3+ in the reaction system while varying the pH. Further, the significant role of cationic surfactant for obtaining the morphology of the spherical nanoparticles of BiVO4 powders with size 55 nm was analyzed. Adsorption behavior of as-synthesized samples was investigated through Langmuir isotherm model. The catalytic performance of BiVO4 photocatalyst with the degradation efficiency of 98.79% and 15.58% over the methylene blue (MB) and methyl orange (MO) dyes were noticed within 60 min of light irradiation respectively. The enhanced and declined catalytic activity was well correlated with the surface charge of BiVO4 photocatalyst towards the MB and MO dyes respectively. Further, the photocatalytic activity of mixed anionic and cationic dyes was performed. The degradation pathway of MB dye was analyzed by LC-MS for the identification of intermediate products. From the obtained results, the proposed possible photocatalytic mechanism reported.

Crystal facet and defect engineering are crucial for designing heterogeneous catalysts. In this study, different solvents were utilized to generate NiO with distinct shapes (hexagonal layers, rods, and spheres) using nickel-based metal-organic frameworks (MOFs) as precursors. It was shown that the exposed crystal facets of NiO with different morphologies differed from each other. Various characterization techniques and density functional theory (DFT) calculations revealed that hexagonal-layered NiO (NiO-L) possessed excellent low-temperature reducibility and oxygen migration ability. The (111) crystal plane of NiO-L contained more lattice defects and oxygen vacancies, resulting in enhanced propane oxidation due to its highest O2 adsorption energy. Furthermore, the higher the surface active oxygen species and surface oxygen vacancy concentrations, the lower the C-H activation energy of the NiO catalyst and hence the better the catalytic activity for the oxidation of propane. Consequently, NiO-L exhibited remarkable catalytic activity and good stability for propane oxidation. This study provided a simple strategy for controlling NiO crystal facets, and demonstrated that the oxygen defects could be more easily formed on NiO(111) facets, thus would be beneficial for the activation of C-H bonds in propane. In addition, the results of this work can be extended to the other fields, such as propane oxidation to propene, fuel cells, and photocatalysis.

The development of Fe-based catalysts for the selective catalytic reduction of NOx by NH3 (NH3-SCR of NOx) has garnered significant attention due to their exceptional SO2 resistance. However, the influence of different sulfur-containing species (e.g., ferric sulfates and ammonium sulfates) on the NH3-SCR activity of Fe-based catalysts as well as its dependence on exposed crystal facets of Fe2O3 has not been revealed. This work disclosed that nanorod-like α-Fe2O3 (Fe2O3-NR) predominantly exposing (110) facet performed better than nanosheet-like α-Fe2O3 (Fe2O3-NS) predominantly exposing (001) facet in NH3-SCR reaction, due to the advantages of Fe2O3-NR in redox properties and surface acidity. Furthermore, the results of the SO2/H2O resistance test at a critical temperature of 250 °C, catalytic performance evaluations on Fe2O3-NR and Fe2O3-NS sulfated by SO2 + O2 or deposited with NH4HSO4 (ABS), and systematic characterization revealed that the reactivity of ammonium sulfates on Fe2O3 catalysts to NO(+O2) contributed to their improved catalytic performance, while ferric sulfates showed enhancing and inhibiting effects on NH3-SCR activity on Fe2O3-NR and Fe2O3-NS, respectively; despite this, Fe2O3-NR showed higher affinity for SO2 + O2. This work set a milestone in understanding the NH3-SCR reaction on Fe2O3 catalysts in the presence of SO2 from the aspect of crystal facet engineering.

Understanding the crystal facet effect in chiral enantiomer recognition plays an important role in designing and fabricating chiral nanozymes for biosensing and biodetection applications. Herein, we design an ideal platform to study the crystal facet effect in chiral enantiomer recognition using cubic and icosahedral PdPt3 hollow nanocages (NCs) as peroxidase mimics via surface ligand decoration of l/d-cysteine (l/d-Cys). The two PdPt3 NCs have the same structure of surface ligand, particle size, wall thickness, surface area, and elemental composition, with the only difference of exposed crystal facets, i.e., {100} for cubic PdPt3 NC-l/d-Cys and {111} for icosahedral PdPt3 NC-l/d-Cys. The cubic PdPt3 {100} facet demonstrates 2.2-fold higher peroxidase-like catalytic activity than the icosahedral PdPt3 {111} facet, which also leads to the better enantiomer recognition performance of discerning 3,4-dihydroxy-l/d-phenylalanine. Our work provides the concept of crystal facet tuning for designing chiral nanozymes with high stereoselective properties.

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Transition metal oxide catalysts have recently gained special interest in alkaline water electrolysis due to their relatively high abundancy and high catalytic activity. However, their catalytic performance has typically been evaluated based on measurements at composite electrodes, that is by immobilizing a large number of these nanoparticles together with inactive binders and additives on a current collector/support and measuring only their integral activity. In such studies, it is challenging to deconvolute the catalyst intrinsic properties from matrix effects. For example, the measured catalytic trends can be influenced by blocking of catalyst active sites by the additives or by non-optimal iR compensation or by different porosity within the composite, impeding a direct comparison of nanocatalysts.[1] Alternatively, single-particle electrocatalysis by the “nano impact” approach has been applied to assess the intrinsic activity of nanoparticles (NPs) at the individual particle level.[2] Exploiting this method, we demonstrate how the catalyst’s crystal facet/shape influences the OER activity by comparing the activity of cubes and spheres of Co3O4.[3] In contrast to the tentative differences in OER activity recorded on ensembles, the single particle studies unambiguously reveal that Co3O4 cubes are more active than spheres when both NPs have otherwise identical parameters. We also can link our experimental data to theory data obtained from DTU+U calculations. Furthermore, we investigate catalyst-support effects and show the higher activity of Pt support than carbon.[4]. This approach enables the identification of highly active facets to guide shape-selective syntheses of improved metal oxide nanocatalysts for water oxidation. References [1] N. Blanc, C. Rurainsky, K. Tschulik, J. Electroanal. Chem. 872(2020)114345 [2] A. El Arrassi, Z. Liu, M. V. Evers, N. Blanc, G. Bendt, S. Saddeler, D. Tetzlaff, D. Pohl, C. Damm, S. Schulz, K. Tschulik, J. Am. Chem. Soc. 141 (2019) 9197 [3] Z. Liu, H. M.A. Amin, Y. Peng, M. Corva, R. Pentcheva, K. Tschulik, Adv. Funct. Mater. 33 (2023) 2210945 [4] Z. Liu, M. Corva, H.M.A. Amin, N. Blanc, J. Linnemann, K. Tschulik, Int. J. Mol. Sci. 22 (2021)13137. Figure: Single particle electrochemistry illustrating the higher OER activity of Co3O4 cubes than spheres. Figure 1

The effect of strong metal-support interaction (SMSI) has never been systematically studied in the field of nanozyme-based catalysis before. Herein, by coupling two different Pd crystal facets with MnO2, i.e., (100) by Pd cube (Pdc) and (111) by Pd icosahedron (Pdi), we observed the reconstruction of Pd atomic structure within the Pd-MnO2 interface, with the reconstructed Pdc (100) facet more disordered than Pdi (111), verifying the existence of SMSI in such coupled system. The rearranged Pd atoms in the interface resulted in enhanced uricase-like catalytic activity, with Pdc@MnO2 demonstrating the best catalytic performance. Theoretical calculations suggested that a more disordered Pd interface led to stronger interactions with intermediates during the uricolytic process. In vitro cell experiments and in vivo therapy results demonstrated excellent biocompatibility, therapeutic effect, and biosafety for their potential hyperuricemia treatment. Our work provides a brand-new perspective for the design of highly efficient uricase-mimic catalysts.

Achieving efficient catalytic oxidation of VOCs by transition metal oxides at low temperatures is a major challenge. Controlling exposed crystal facets through crystal facet engineering is an efficient strategy for enhancing the catalytic activity of catalysts. Herein, we proposed an anion-inducted method for precisely modulating the exposed crystal facets on Co3O4 catalysts by using different types of cobalt salts. The Co3O4-a catalyst with highly exposed (220) facets exhibits exceptional catalytic performance, achieving 90% conversion of benzene and toluene at 239 and 240 °C, respectively, which are significantly lower than the temperatures required for Co3O4-s (286 and 299 °C). The specific reaction rates of Co3O4-a for benzene and toluene catalytic oxidation were 19.7 × 10-9 mol/m2/s and 15.5 × 10-9 mol/m2/s, which were 3.1 times and 19.4 times than that of Co3O4-s (6.3 × 10-9 mol/m2/s and 0.8 × 10-9 mol/m2/s), respectively. The excellent activity of Co3O4-a catalyst was due to stronger interactions between the tetra-coordinated cobalt atoms (Co4c) on the (220) crystal plane with reactants by in situ DRIFTS and DFT results. The Co4c sites act as bifunctional active centers, simultaneously inducing CC bond elongation in aromatic hydrocarbons and OO bond activation in O2, which the pre-activation of adsorbed molecules can lower the energy barriers for CH cleavage and ring-opening reactions, and ultimately promotes the deep oxidation of VOCs. This research deepens the understanding of surface structure-oriented catalysis in VOCs oxidation, while aiding the rational design of advanced catalysts.

Although heterogeneous photo‐Fenton reactions on nanoparticulate iron oxides effectively degrade organic pollutants, the underlying surface mechanisms remain debated. Here, we demonstrate how these pathways are modulated by specific hematite crystal facets. To investigate the influence of particle surface structure, methylene blue (MB) adsorption and photodegradation kinetics are examined using facet‐engineered hematite nanoparticles with distinct exposed facets. The results reveal that MB photodegradation strongly depends on both pH and facet orientation. When normalized by surface area, (116) facet shows higher photodegradation activity than those with (104) or (001) facets. This enhanced activity is attributed to favorable electronic structure and surface characteristics, including a smaller optical bandgap, faster charge transfer, and superior H2O2 decomposition. In contrast, the photodegradation capacity follows (104) 〉 (116) 〉 (001), primarily due to the higher density of surface‐active sites on the (104) facet. These sites promote coupled MB adsorption and degradation, enabling removal of a greater overall quantity of MB. Additionally, under high pH conditions, hematite can degrade MB in the dark, with capacities following (001) ≫ (116) 〉 (104). These findings underscore the critical catalytic role of specific hematite surfaces and advance the understanding of facet‐dependent photoinduced redox chemistry at mineral–water interfaces.

Electrocatalysts are the cornerstone in the transition to sustainable energy technologies and chemical processes. Surface transformations under operation conditions dictate the activity and stability. However, the dependence of the surface structure and transformation on the exposed crystallographic facet remains elusive, impeding rational catalyst design. We investigate the (001), (110) and (111) facets of a LaNiO3−δ electrocatalyst for water oxidation using electrochemical measurements, X-ray spectroscopy, and density functional theory calculations with a Hubbard U term. We reveal that the (111) overpotential is ≈ 30−60 mV lower than for the other facets. While a surface transformation into oxyhydroxide-like NiOO(H) may occur for all three orientations, it is more pronounced for (111). A structural mismatch of the transformed layer with the underlying perovskite for (001) and (110) influences the ratio of Ni2+ and Ni3+ to Ni4+ sites during the reaction and thereby the binding energy of reaction intermediates, resulting in the distinct catalytic activities of the transformed facets.

Designing an effective Pd-Pt catalytic material with excellent catalytic performance for perhydroacenaphthene (PHAN) dehydrogenation is a great challenge. In this work, in order to explore the crystal facet structure over the bimetallic Pd-Pt catalyst on the dehydrogenation performance of PHAN, the surface compositions of two kinds of Pd (Pt) atoms with different coverage on Pd modulated Pt (PdPt) and Pt modulated Pd (PtPd) catalysts were designed and studied by means of density functional theory (DFT). Through the investigation of the reaction path of PHAN dehydrogenation on PdMLPt(111) and PtMLPd(111) surfaces, it was found that PdMLPt(111) was advantageous to PHAN dehydrogenation (Ea = 2.317 eV). This was attributed to a lower energy barrier, more stable dehydrogenation products, and the fact that Pd doping brought Pt(111) close to the Fermi level. Apparently, Pd modulated Pt catalyst has a broad application prospect in the dehydrogenation of PHAN. In the process of optimizing the PdPt morphology, a method for selecting the minimum active unit of PdPt catalysts with different ratios was proposed, that is, the most stable active unit: rhombus structure was determined according to the surface formation energy. Moreover, we correlated the relationship among the number of H atoms removed, adsorption energy, surface charge, activation energy, reaction energy, and surface coverage, and obtained the important parameters to predict the performance of PdPt catalyst in PHAN dehydrogenation system: surface charge and d-band center. Finally, the essential correlativity among Pd-Pt surface characteristics, catalytic PHAN activity, and adsorption energy was constructed; that is, the relationship model among d-band center, H atom, and product C12H8 adsorption energy was established. This work opens a new simultaneous path to improve the catalytic performance of Pd-Pt-based catalytic materials for PHAN dehydrogenation, which can be achieved by regulating the rhombic active units of Pt modulated by Pd.

Catalytic oxidation is an effective method for removing methanol emitted from industrial production and the combustion of methanol as a clean energy source. In this work, the mechanism of the catalytic oxidation of methanol on CeO2 with various morphologies (nanorods, nanoparticles, and nanocubes) and hence different exposed crystal facets was studied by various designed experiments and density functional theory (DFT) calculation. It was demonstrated that the oxidation of methanol on the CeO2 surface follows the reaction pathway of CH3OH → -CH3O → HCHO → HCOOH → CO + H2O → CO2. The activation of O2 was the rate-determining step of the entire catalytic oxidation reaction. CeO2 nanorod-exposed (111) and (100) facets exhibited superior catalytic activity due to their rich oxygen vacancies and surface Oads compared with the CeO2 nanoparticle mainly exposed (111) facet and the CeO2 nanocube mainly exposed (100) facet. When considering the specific surface area, nanocubes had the highest specific activity as the (100) facet has a stronger ability for O2 activation than the (111) facet. These findings clarified the reaction pathway and rate-determining step of methanol oxidation on CeO2-based catalysts and provided valuable insights into the development of high-performance catalysts for oxygen-containing VOC oxidation.

Rational regulation of photogenerated charge carrier separation and transfer is a key strategy for optimizing photocatalytic activity. Leveraging the synergistic effects of crystal facet engineering and the piezoelectric effect, a series of hexagonal Zinc oxide (ZnO) photocatalysts with varying exposure ratios of the {002} and {210} facets were successfully synthesized and employed under simultaneous excitation by simulated sunlight and ultrasound. As expected, compared to amorphous ZnO, the hexagonal ZnO samples demonstrated a significant enhancement in piezo-photocatalytic tetracycline hydrochloride degradation and polyethylene terephthalate reforming processes. In-depth investigations confirm that the pronounced piezo-photocatalytic performance of the hexagonal ZnO samples is attributed to the synergistic effect of the built-in electric field formed at the facet junctions and the polarization electric field generated by the piezoelectric effect, both of which significantly influence charge separation and carrier mobility. These findings offer new strategies for improving catalytic efficiency and advancing sustainable technologies through photocatalysis.

Atomic dispersed metal sites in single-atom catalysts are highly mobile and easily sintered to form large particles, which deteriorates the catalytic performance severely. Moreover, lack of criterion concerning the role of the metal-support interface prevents more efficient and wide application. Here, a general strategy is reported to synthesize stable single atom catalysts by crafting on a variety of cobalt-based nanoarrays with precisely controlled architectures and compositions. The highly uniform, well-aligned, and densely packed nanoarrays provide abundant oxygen vacancies (17.48%) for trapping Pd single atoms and lead to the creation of 3D configured catalysts, which exhibit very competitive activity toward low temperature CO oxidation (100% conversion at 90 °C) and prominent long-term stability (continuous conversion at 60 °C for 118 h). Theoretical calculations show that O vacancies at high-index {112} facet of Cox Oy nanocrystallite are preferential sites for trapping single atoms, which guarantee strong interface adhesion of Pd species to cobalt-based support and play a pivotal role in preventing the decrement of activity, even under moisture-rich conditions (≈2% water vapor). The progress presents a promising opportunity for tailoring catalytic properties consistent with the specific demand on target process, beyond a facile design with a tunable metal-support interface.

Defects engineering in metal oxide is an important avenue for the promotion of VOCs catalytic oxidation. Herein, the influence of crystal facet of Co3O4 is first investigated for the propane oxidation. An intelligent Cu doping is subsequently performed in the most active (110) facet exposed Co3O4 catalyst. The optimized Cu-Co3O4-110-3 catalyst exhibits a prominently enhanced activity with propane conversion rate of 1.9 μmol g-1 s-1 at reaction temperature of 192 °C and the propane mass space velocity of 60,000 mL g-1 h-1, about 2.4 times that of the pristine Co3O4. Systematic experimental characterizations (XAS, EPR, Raman, TPR, XPS, etc.) combined with density functional theory calculations point out that the incorporated Cu could increase the electrophilicity of nearby O atom and implant beneficial defect structures (lattice distortion, coordination unsaturation, abundant oxygen vacancies, etc.), which could significantly activate Co-O bond in Co3O4, leading to the facilitated generation of active oxygen species as well as promoted oxidation ability. This study could set an illuminating paradigm for the boost of the intrinsic oxidation activity by the precise defect construction in Co3O4 catalyst, which will help drive ahead the pursuit of non-precious metal catalyst for VOCs abatement.

The use of WO3 as an acid catalyst has received extensive attention in recent years. However, the correlation between the catalytic activity and the predominantly exposed surface with varied acidic sites needs further understanding. Herein, the effects of the Brønsted and Lewis acid sites of different crystal facets of WO3 on the catalytic conversion of furfuryl alcohol (FA) to ethyl levulinate (EL) in ethanol were investigated in detail. A yield of EL up to 93.3% over WO3 with the (110) facet exposed was achieved at 170 °C, while FA was mainly converted to polymers over (001) faceted nanosheets and nanobelts with exposed (002) and (100) facets. This was attributed to the different distribution of the acidic sites on different exposed crystal facets. The (110) faceted WO3 possessed abundant and strong Brønsted acid sites, which favored the conversion of FA to EL, while the (100) faceted WO3 with stronger Lewis acid sites and weaker Brønsted acid sites mainly led to the formation of polymers. In addition, the (110) faceted WO3 showed excellent sustainability in comparison with the (100) faceted counterpart.

The exposed facets of supported metal catalysts play a crucial role in catalytic hydrogenation performance. However, the internal relationship between the support crystal facet and catalytic performance needs to be further explored. Herein, a series of well-defined Pt/Co3O4-x catalysts are fabricated with similar Pt nanoparticle sizes, identical metal loadings, and tailored Co3O4 crystal facets (x = o, t, c; where "o", "t", and "c" denote Co3O4 exposing predominantly (111), mixed (111)/(100), and (100) facets, respectively). The electronic structure of Pt nanoparticles and the hydrogen spillover capability of Pt/Co3O4 are modulated by exposing different crystal facets of Co3O4. For the 4-nitrophenol (4-NP) hydrogenation reaction with H2 as the hydrogen source, the Pt/Co3O4-o catalyst with more Pt0 species and stronger hydrogen spillover capability exhibits the best hydrogenation activity with a turnover frequency (TOF) of 164.2 h-1. Mechanistic studies indicate that, compared with Pt/Co3O4-c, the Pt/Co3O4-o exhibits weaker adsorption and activation of the nitro group, while its ability to activate H2 is stronger. The enhanced catalytic activity of Pt/Co3O4-o is attributed to promoted hydrogen activation and spillover. This work highlights support crystal facet engineering for regulating the electronic structure and hydrogen spillover effect, which provides in-depth insight into catalyst design and hydrogenation mechanism.

Carbon quantum dots were successfully doped into anatase TiO2 single crystal nanosheets (TNS) with exposed {001} and {101} reactive facets by a facile solvothermal process. SEM and TEM confirmed the as-prepared TiO2 nanosheet structure and that the dominant exposed face is the {001} facet, and the loaded N-CDs are nearly spherical with an average size of about 3 nm. XPS results confirmed that the deposited N-CDs were chemically integrated into the TiO2 nanosheets. UV-vis DRS spectroscopy shows that with the dotting of N-CDs, the absorption edge of N-CDs/TNS has been extended into the visible light region. The ability of the N-CDs/TNS to degrade Rhodamine B (RhB) in aqueous solution under visible light irradiation (λ ≥ 400 nm) was investigated. The results show that the photocatalytic performance of N-CDs/TNS was substantially improved relative to pure TNS. The photodegradation efficiency reached its maximum value with 6 mL of N-CDs/TNS, showing a 9.3-fold improvement in photocatalytic activity over TNS. Fluorescence spectroscopy (PL) and electron paramagnetic resonance (EPR) studies were conducted to characterize the active species during the degradation period, based on which the possible photodegradation mechanism of N-CDs/TNS by visible light irradiation was given.

Crystalline structure and bimetallic interaction of metal oxides are essential factors to determine the catalytic activity. Herein, three different CoOx/CeO2 catalysts, employing CeO2 nanorods (predominately exposed {110 facet), CeO2 nanopolyhedra ({111} facet) and CeO2 nanocubes ({100} facet) as the supports, are successfully prepared for investigating the effect of exposed crystal facets and bimetallic interface interaction on NO oxidation. In comparison with the {111} and {100} facets, the exposed crystal facet {110} exists the best superiority to anchor and stabilize Co species. Moreover, ultra-small CoOx clusters composed of strong Co-O coordination shells with minor Co-O-Ce interaction are formed and uniformly dispersed on the CeO2 nanorods. Structural characterizations reveal that the active exposed crystal facet {110} and the strong bimetallic interface interaction in CoOx/CeO2-nanorods (R-CC) result in more structural defect, endowing it with abundant oxygen vacancies, excellent reducibility and strong adsorption capacity. The DRIFTs spectra further indicate that the exposed crystal facet {110} has a significant promoting effect on the strength of nitrates compared with {111} and {100} facets. The bimetallic interface interaction not only significantly facilitates the formation of nitrate species at lower temperature, but also effectively suppresses the generation of sulfate and lower the sulphation rate. Therefore, R-CC catalyst exhibits the maximum NO oxidation activity with the conversion of 86.4 % at 300 °C and still sustains its high activity under cyclic condition or 50 ppm SO2. The provided crystalline structure and interaction-enhanced strategy sheds light on the design of high-activity NO oxidation catalysts.

Amino acids are widely used in food, pharmaceuticals, and agrochemicals, presenting significant societal demand, and the artificial synthesis of amino acids is an important yet challenging task. Through electrocatalytic C–N coupling, the synthesis of amino acids from biomass α-keto acids and waste nitrate under mild aqueous conditions has become a green and alternative strategy. Rare-earth-based materials, due to their unique 4f orbitals and tunable crystal facets, often serve as potential resource-rich catalysts. However, their structure–performance relationship in C–N coupling for amino acids synthesis remains unclear. Therefore, eight rare-earth-based catalysts were screened in this work and CeO2 was chosen as an appropriate model catalyst for the mechanism investigation on the electrosynthesis of alanine. Four CeO2 nanomaterials with distinct morphologies and crystal facets were synthesized, among which CeO2 nanorods (CeO2-NRs) exposing the (110) facet exhibited the highest oxygen vacancy (Ov) concentration and optimal electrosynthetic performance for alanine. A series of control experiments, electrochemical characterizations, in situ electrochemical attenuated total reflection Fourier transform infrared spectroscopy (in situ ATR-FTIR), online electrochemical differential mass spectrometry (DEMS), quasi in situ electron paramagnetic resonance (quasi in situ EPR) experiments, combined with density functional theory (DFT) calculations indicated that the synthesis pathway for alanine involved the reduction of NO3– to produce *NH2OH in situ, which nucleophilically attacked the carbonyl group of pyruvate to form the key intermediate species, oxime, then underwent further amination to generate alanine. The key step responsible for the performance difference of four CeO2 nanocrystals lay in the reduction amination of pyruvate oxime (PO), confirming the (110) facet with more Ov exposure facilitated the cleavage of the N–O bond in pyruvate oxime (*OOC(H3C)C=N–OH→*OOC(H3C)C=N), while also lowering the energy consumption for the hydrogenation of the C=N bond (*OOC(H3C)C=NH→*OOC(H3C)CNH2). This innovative strategy not only provides a new route for the valorization of biomass and waste nitrate but also offers valuable guidance for the design of more efficient rare-earth-based catalysts in this field.

No abstract available

No abstract available

Controllable fabrication of single-crystal metal oxide is of paramount importance for advanced photo(electro)catalytic applications, but achieving non-equilibrium crystal shapes with tailored facets through molten salt synthesis still remains a challenge. Herein, we systematically explored the effect of Al3+ concentration in tailoring crystal facets of SrTiO3 single crystals, and developed a one-step molten salt strategy for engineering anisotropic structures by using miscible AlCl3 as Al3+ additive. By progressively increasing Al3+ concentration, a series of high-quality SrTiO3 single crystals exposing {100}, {111} and {110} facets were sequentially synthesized. Theoretical calculations reveal an Al-doping stabilized {111} surface reconstruction, and provide further atomistic insights into the surface structural evolution with Wulff constructions as Al3+ concentration increases. Experimental results demonstrate that the anisotropic facets dominate the efficient charge separation for the enhanced photocatalytic overall water splitting activity. Consequently, SrTiO3 single crystals enclosed by well-defined {100} and {111} facets exhibit a remarkable hydrogen evolution rate of 2621.85 μmol·h-1 and an apparent quantum yield value of 50.5% at 350 nm for stoichiometric overall water splitting. This work offers a molten-salt synthetic strategy and valuable insight for preparing facet-controlled single-crystal semiconductors.

Developing a facile strategy to activate the inert crystal face of an electrocatalyst is critical to full-facet utilization, yet still challenging. Herein, the electrocatalytic activity of the inert crystal face is activated by quenching Co3 O4 cubes and hexagonal plates with different crystal faces in Fe(NO3 )3 solution, and the regulation mechanism of facet-dependent quench-engineering is further revealed. Compared to the Co3 O4 cube with exposed {100} facet, the Co3 O4 hexagonal plate with exposed {111} facet is more responsive to quenching, accompanied by a rougher surface, richer defect, and more Fe doping. Theoretical calculations indicate that the {111} facet has a more open structure with lower defect formation energy and Fe doping energy, ensuring its electronic and coordination structure is easier to optimize. Therefore, quench-engineering largely increases the catalytic activity of {111) facet for oxygen evolution reaction by 13.2% (the overpotential at 10 mA cm-2 decreases from 380 to 330 mV), while {100} facet only increases by 7.6% (from 393 to 363 mV). The quenched Co3 O4 hexagonal plate exhibits excellent electrocatalytic activity and stability in both zinc-air battery and water-splitting. The work reveals the influence mechanism of crystal face on quench-engineering and inspires the activation of the inert crystal face.

Interest in the green synthesis of PLA-Ag2O-TiO2 nanoparticles has exploded in recent decades due to the need to develop cost-effective and environmentally friendly processes. A novel method to develop different kinds of nanomaterials is green synthesis. This study employed an eco-friendly synthesis method that produced Ag2O-TiO2 nanoparticles (NPs) using polylactic acid (PLA). The XRD pattern of TiO2 powder containing 1 mmol of silver nitrate with leaf extract, the crystal phase is found to be anatase in all samples. The FTIR spectra show peaks for O-H stretching vibrations, bending vibrations, and Ti-OH surface groups. Co-doped TiO2 intensity reduces, with efficient dispersion of silver, and no clusters. The morphology and structure of the prepared samples were examined using Scanning Electron Microscopy (SEM), revealing a spherical Ag2O-TiO2 nanocomposite with slightly agglomerated powder particles. The size was determined using transmission electron microscopy (TEM). The size of leaf extract Ag2O-TiO2 nanoparticles were30 ± 5 nm. The study investigated the photocatalytic properties of pesticide residues in water, with a nanocatalyst. The samples were exposed to sunlight and filtered through a 0.45µm PTFE membrane filter. The findings revealed that the presence of a catalyst significantly reduced the samples' half-life, indicating that nanoparticles are an effective photocatalyst for removing pesticide residues.

Interface engineering and vacancy engineering play an important role in the surface and electronic structure of nanomaterials. The combination of the two provides a feasible way for the development of efficient photocatalytic materials. Here, we use glutathione (GSH) as a coordination molecule to design a series of CuxS nanomaterials (CuxS-GSH) rich in sulfur vacancies using a simple ultrasonic-assisted method. Interface engineering can induce amorphous structure in the crystal while controlling the formation of porous surfaces of nanomaterials, and the formation of a large number of random orientation bonds further increases the concentration of sulfur vacancies in the crystal structure. This study shows that interface engineering and vacancy engineering can enhance the light absorption ability of CuxS-GSH nanomaterials from the visible to the near-infrared region, improve the efficiency of charge transfer between CuxS groups, and promote the separation and transfer of optoelectronic electron-hole pairs. In addition, a higher specific surface area can produce a large number of active sites, and the synergistic and efficient photothermal conversion efficiency (58.01%) can jointly promote the better photocatalytic performance of CuxS-GSH nanomaterials. Based on the excellent hot carrier generation and photothermal conversion performance of CuxS-GSH under illumination, it exhibits an excellent ability to mediate the production of reactive oxygen species (ROS) through peroxide cleavage and has excellent peroxidase activity. Therefore, CuxS-GSH has been successfully developed as a nanoenzyme platform for detecting tannic acid (TA) content in tea, and convenient and rapid detection of tannic acid is achieved through the construction of a multi-model strategy. This work not only provides a new way to enhance the enzyme-like activity of nanomaterials but also provides a new prospect for the application of interface engineering and vacancy engineering in the field of photochemistry.

Indoor formaldehyde pollution seriously jeopardizes human health. The development of efficient and stable non-precious metal catalysts for low-temperature catalytic degradation of formaldehyde is a promising approach. In this study, TiO2 {001} and {101} supports were loaded with different ratios of Mn and Ce active components, and the effects of the ratios of the active components on the catalytic activity were investigated. The elemental oxidation states, redox capacities, active oxygen mobilities and acid site distributions of the catalysts were determined using characterization techniques such as XPS, H2-TPR, O2-TPD, and NH3-TPD. In situ infrared spectroscopy was utilized to reveal the differences in the two-step dehydrogenation reactions of dioxymethylene (DOM) in 5Mn1Ce/Ti-NS and 5Mn1Ce/Ti-NP. Density-functional theory was used to investigate the differences in the catalytic steps and maximum energy barriers of Mn-Ce/Ti-NS and Mn-Ce/Ti-NP for HCHO. The differences in catalytic activity due to the influence of the manganese and cerium active components on the {001} and {101} crystal faces of anatase titanium dioxide are comprehensively revealed. Exposure of the supported crystalline surfaces alters the catalytic activity centers and reaction pathways at the molecular level. This study provides experimental and theoretical guidance for the selection of exposed crystalline surfaces for loaded catalysts.

Optimized surface facet of the catalysts is an efficient strategy to boost catalytic purification of diesel soot as important components of atmospheric fine particles. Herein, we have elaborately constructed the nanocatalysts of Au nanoparticles (NPs) supported on the well-defined CeO2 (rod, cube and polyhedron) with predominantly exposed facets of {110}, {100} and {111}, respectively. The strong interaction between Au and CeO2 with optimal crystal facet is crucial to adjust the active site density for activated O2, and the synergy effect of Au and CeO2{110} facet possesses the largest density of active sites compared with other crystal facets of {100} and {111}. The catalytic activity for soot combustion was tuned by exposed crystal facets of CeO2. Au/CeO2-rod catalyst exhibits the highest catalytic activity (T50=350 °C, TOF=0.18 h-1) and the lowest apparent activation energy (72 kJ mol-1) during soot combustion. Based on the results of in-situ Raman spectra, the formation and stability of oxygen vacancy located at the interface of Au-O-Ce bond, boosting the key step of NO oxidation to NO2, are dependent on the exposed crystal facets of CeO2. It highlights a new strategy to the fabrication of high-efficient CeO2-based catalysts for removal of soot particles or other pollutions.

Accurate identifying and in-depth understanding of the defect sites in a working nanomaterial could hinge on establishing specific defect-activity relationships. Yet, atomically precise coinage-metal nanoclusters (NCs) possessing surface vacancy defects are scarce primarily owing to challenges in the synthesis and isolation of such defective NCs. We report a mixed-ligand strategy to synthesizing an intrinsically chiral and metal-deficient copper hydride-rich NC [Cu57H20(PET)36(TPP)4]+ (Cu57H20). Its total structure (including hydrides) and electronic structure are established by combined experimental and computational results. Crystal structure reveals Cu57H20 features a cube-like Cu8 kernel embedded in a corner-missing metal-ligand shell of Cu49(PET)36(TPP)4. Single Cu vacancy defect occurs at one corner of the shell, evocative of mono-lacunary polyoxometalates. Theoretical calculations demonstrate that the above-mentioned point vacancy causes one surface hydride exposed as an interfacial capping μ3-H-, which is accessible in chemical reaction, as proved by deuterated experiment. Moreover, Cu57H20 shows catalytic activity in the hydrogenation of nitroarene. The success of this work opens the way for the research on well-defined chiral metal-deficient Cu and other metal NCs, including exploring their application in asymmetrical catalysis.

No abstract available

No abstract available

Tuning the surface chemical property and the local environment of nanocrystals is crucial for realizing a high catalytic performance in various reactions. Herein, we aim to elucidate the structure sensitivity of Pd facets on the surface catalytic hydrogenation reaction and to identify what role the nanoconfinement effect plays in the catalytic properties of Pd nanocrystal catalysts. By controlling the coating structures of mesoporous silica (mSiO2) on Pd nanocrystals with different exposed facets that include {100}, {111}, and {hk0}, we present a series of Pd@mSiO2 nanoreactors in core-shell and yolk-shell structures and the discovery of a partial-coated structure, which can provide different types of nanoconfinement, and we propose a seed size-dominated growth mechanism. We demonstrate that a superior activity was exhibited in Pd nanocrystals enclosed by the {hk0} facet as compared to the Pd{100} and Pd{111} facets, and substantially enhanced efficiency and stability were achieved in Pd@mSiO2 particles with yolk-shell structures, indicating a crucial superiority of optimizing the configuration of crystal facets and nanoconfinement. Our study provides an efficient strategy to rationally design and optimize nanocatalysts for promoting catalytic performance.

We present a simple and cost-effective molten salt synthetic route toward phase-pure perovskite cobaltite microcrystallines and successfully regulate different crystal facets for perovskite LaCoO3 by the strong interaction between Cl- anions and Sr2+ cations in molten salt system and polar plane. We then take LaCoO3 (100 and 110), LaCoO3 (111), and La0.7Sr0.3CoO3 (111) as comparison models, and we characterize their crystal structure, morphology, composition, electronic state, and catalytic properties. X-ray photoelectron spectroscopy (XPS) shows that the prepared samples with high-energy (111) crystal facets contain more surface oxygen species and active Co ions than La enrichment perovskite LaCoO3 (110 and 100) on the surface. Furthermore, combining with ambient-pressure XAS, valence band spectroscopy, and density functional calculations, we find that exposed high-energy (111) crystal facets and doping Sr ions can enhance the hybridization between Co cations and O anions and their O p-band center is closer to the Fermi level, compared with that of LaCoO3 (100 and 110). As expected, the samples with high-energy (111) crystal facets show better CO oxidation activity than LaCoO3 (100 and 110), and La0.7Sr0.3CoO3 (111) exhibits the highest catalytic activity. Our findings provide a new avenue to prepare high-energy facet perovskite catalysts and we also clearly reveal the relationship between surface electronic structure and intrinsic CO oxidation activity of perovskite cobaltite.

Chiral metal halide perovskites have garnered substantial interest because of their promising properties for application in optoelectronics and spintronics. Understanding the mechanism of chiral imprinting is paramount for optimizing their utility. To elucidate the nature of the underlying chiral imprinting mechanism, we investigated how the circular dichroism (CD) intensity varies with nanoparticle size for quantum confined sizes of colloidal CsPbBr3 perovskite nanoparticles (NPs) capped by chiral β-methylphenethylammonium bromide ligands. We find that the CD intensity decreases strongly with increasing NP size, which, along with the shape of the CD spectra, points to electronic interactions between ligand and NP as the dominant mechanism of chiral imprinting in smaller NPs. We observe that as the NP size increases and crosses the quantum confinement threshold, the dominant mechanism of chirality transfer switches and is dominated by surfaces effects, e.g., structural distortions. These findings provide a benchmark for quantitative models of chiral imprinting.

Hydroxyapatite nanoparticles (nHA) have gained attention as potential intracellular drug delivery vehicles due to their high binding affinity for various biomolecules and pH-dependent solubility. Yet, the dependence of nHA cytocompatibility on their physicochemical properties remains unclear since numerous studies have revealed starkly contrasting results. These discrepancies may be attributed to differences in size, shape, crystallinity, and aggregation state of nHA, which complicates fundamental understanding of the factors driving nHA cytotoxicity. Here, we hypothesize that nHA cytotoxicity is primarily driven by intracellular calcium levels following the internalization of nHA nanoparticles. By investigating the cytotoxicity of spherical nHA with different crystallinity and dispersity, we find that both lower crystallinity and increased agglomeration of nHA raise cytotoxicity, with nanoparticle agglomeration being the more dominant factor. We show that the internalization of nHA enhances intracellular calcium levels and increases the production of reactive oxygen species (ROS). However, only subtle changes in intracellular calcium are observed, and their physiological relevance remains to be confirmed. In conclusion, we show that nHA agglomeration enhances ROS production and the associated cytotoxicity. These findings provide important guidelines for the future design of nHA-containing formulations for biomedical applications, implying that nHA crystallinity and especially agglomeration should be carefully controlled to optimize biocompatibility and therapeutic efficacy.

Controlling the spatial arrangement of plasmonic nanoparticles is of particular interest to utilize inter-particle plasmonic coupling, which allows changing their optical properties. For bottom-up approaches, colloidal nanoparticles are interesting building blocks to generate more complex structures via controlled self-assembly using the destabilization of colloidal particles. For plasmonic noble metal nanoparticles, cationic surfactants, such as CTAB, are widely used in synthesis, both as shaping and stabilizing agents. In such a context, understanding and predicting the colloidal stability of a system solely composed of AuNPs and CTAB is fundamentally crucial. Here, we tried to rationalize the particle behavior by reporting the stability diagrams of colloidal gold nanostructures taking into account parameters such as the size, shape, and CTAB/AuNP concentration. We found that the overall stability was dependent on the shape of the nanoparticles, with the presence of sharp tips being the source of instability. For all morphologies evaluated here, a metastable area was systematically observed, in which the system aggregated in a controlled way while maintaining the colloidal stability. Combining different strategies with the help of transmission electron microscopy, the behavior of the system in the different zones of the diagrams was addressed. Finally, by controlling the experimental conditions with the previously obtained diagrams, we were able to obtain linear structures with a rather good control over the number of particles participating in the assembly while maintaining good colloidal stability.

No abstract available

The synthesis, morphological characterization, and optical properties of colloidal, Eu(III) doped Gd2O3 nanoparticles with different sizes and shapes are presented. Utilizing wet chemical techniques and various synthesis routes, we were able to obtain spherical, nanodisk, nanotripod, and nanotriangle-like morphology of Gd2O3:Eu3+ nanoparticles. Various concentrations of Eu3+ ions in the crystal matrix of the nanoparticles were tested in order to establish the levels at which the concentration quenching effect is negligible. Based on the luminescence spectra, luminescence lifetimes and optical parameters, which were calculated using the simplified Judd–Ofelt theory, correlations between the Gd2O3 nanoparticles morphology and Eu3+ ions luminescence were established, and allowed to predict the theoretical maximum quantum efficiency to reach from 61 to 98 %. We have also discussed the impact of the crystal structure of Gd2O3 nanoparticles, as well as coordinating environment of luminescent ions located at the surface, on the emission spectra. With the use of a tunable femtosecond laser system and the Z-scan measurement technique, the values of the effective two-photon absorption cross-section in the wavelength range from 550 to 1,200 nm were also calculated. The nonlinear optical measurements revealed maximum multi-photon absorption in the wavelength range from 600 to 750 nm.

Gold nanoparticles (AuNPs) were synthesized via two complementary routes, an inorganic surfactant-mediated method and a plant-extract-assisted biosynthesis, to elucidate how synthesis pathways influence nanoparticle physicochemical properties. In the inorganic route, hexadecyltrimethylammonium bromide (CTAB)-stabilized AuNPs were prepared using CTAB dissolution temperatures of 70–90 °C. UV–Vis spectroscopy showed localized surface plasmon resonance (LSPR) bands at 554–556 nm, while dynamic light scattering (DLS) indicated a decrease in hydrodynamic diameter from 110 to 97 nm with increasing dissolution temperature. Zeta potentials above +40 mV indicated strong electrostatic stabilization, and transmission electron microscopy (TEM) revealed ultrasmall Au cores with a narrow size distribution (2.4–3.0 nm) and a face-centered cubic crystal structure. In the biosynthetic route, AuNPs were obtained using aqueous Erythroxylum coca leaf extracts (1–4% w/v). The extracts exhibited a concentration-dependent red shift (~380 to ~420 nm), and biosynthesized AuNPs displayed LSPR bands in the 550–580 nm range. DLS yielded hydrodynamic diameters of 270–390 nm, with pronounced aggregation (3341 nm) at the lowest extract concentration. Under optimized conditions (HC5, n = 5), reproducible plasmonic and colloidal properties were obtained (maximum absorbance, localized surface plasmon resonance wavelength (λmax) = 569.6 ± 1.7 nm; hydrodynamic diameter (DH) = 237.6 ± 24.3 nm; absolute zeta potential (|ζ|)= 32.2 ± 2.6 mV). TEM analysis indicated predominantly quasi-spherical particles with a broader, log-normal size distribution, consistent with extract-mediated growth under heterogeneous organic capping environments.

The single nanoparticle (NP) collision strategy offers a promising alternative to traditional ensemble methods in electrocatalysis, providing unique insights into catalytic behavior that cannot be captured by ensemble-based techniques. However, synthesizing colloidal NP catalysts with tunable composition, uniform size, and near-pristine surfaces remains a significant challenge. Here, using PtxRu1-x alloys as a model system, we propose an innovative strategy that combines ultrafast high-temperature precision synthesis with ultrasonic exfoliation. This approach enables the preparation of colloidal catalysts with the desired properties, which were previously difficult to achieve. Single NP collision electrocatalysis uncovers the composition-dependent intrinsic activity of the methanol oxidation reaction (MOR) at industrial current densities, bypassing mass transfer limitations. Density functional theory (DFT) calculations highlight the Pt-Ru synergistic effect in optimizing MOR performance. This study, for the first time, integrates ultrafast precision synthesis with single NP electrocatalysis, providing a new framework for the development of highly efficient catalysts.

Nanostructures exfoliated from layered van der Waals materials have attracted attention based upon their thickness-dependent optical and electronic properties. While magnetism has been observed in such 2D materials, available approaches to modulate or enhance their magnetic response remain limited. Thus, the magnetic response of 2D materials is of particular interest. Relatively few reports focus on colloidal routes to synthesize layered materials from which 2D nanostructures can be obtained by exfoliation. Herein, we present a general method to synthesize bulk vanadium diselenide (VSe2) and dual-phase tin diselenide SnSe2–SnSe followed by liquid phase redox exfoliation to delaminate these materials into 2D nanostructures of different thicknesses. The delamination process induces phase changes, affecting the overall magnetic and optical behavior. The magnetization of these 2D nanostructures of different thicknesses increases with an increasing exfoliation degree (decreasing size and thickness). Moreover, we decorated these 2D nanostructures with colloidally synthesized iron oxide dots (FexOy, ∼4 nm diameter). This enhanced the magnetic response, which reached a saturation magnetization of 32 emu g−1 for VSe2–FexOy and 2.7 emu g−1 for SnSe2–FexOy. A synergistic effect is observed, in which the magnetization of the FexOy decorated VSe2 significantly exceeds that of either FexOy itself or VSe2 alone. This report provides a general method to synthesize 2D nanostructures of varied thickness and to decorate them with magnetic nanoparticles to achieve synergistic magnetic response.

No abstract available

The widespread use of magnetic nanoparticles in the biotechnical sector puts new demands on fast and quantitative characterization techniques for nanoparticle dispersions. In this work, we report the use of asymmetric flow field-flow fractionation (AF4) and ferromagnetic resonance (FMR) to study the properties of a commercial magnetic nanoparticle dispersion. We demonstrate the effectiveness of both techniques when subjected to a dispersion with a bimodal size/magnetic property distribution: i.e., a small superparamagnetic fraction, and a larger blocked fraction of strongly coupled colloidal nanoclusters. We show that the oriented attachment of primary nanocrystals into colloidal nanoclusters drastically alters their static, dynamic, and magnetic resonance properties. Finally, we show how the FMR spectra are influenced by dynamical effects; agglomeration of the superparamagnetic fraction leads to reversible line-broadening; rotational alignment of the suspended nanoclusters results in shape-dependent resonance shifts. The AF4 and FMR measurements described herein are fast and simple, and therefore suitable for quality control procedures in commercial production of magnetic nanoparticles.

The catalytic and plasmonic properties of bimetallic gold–palladium (Au-Pd) nanoparticles (NPs) critically depend on the distribution of the Au and Pd atoms inside the nanoparticle bulk and at the surface. Under operating conditions, the atomic distribution is highly dynamic. Analyzing gas induced redistribution kinetics at operating temperatures is therefore key in designing and understanding the behavior of Au-Pd nanoparticles for applications in thermal and light-driven catalysis, but requires advanced in situ characterization strategies. In this work, we achieve the in situ analysis of the gas dependent alloying kinetics in bimetallic Au-Pd nanoparticles at elevated temperatures through a combination of CO-DRIFTS and gas-phase in situ transmission electron microscopy (TEM), providing direct insight in both the surface- and nanoparticle bulk redistribution dynamics. Specifically, we employ a well-defined model system consisting of colloidal Au-core Pd-shell NPs, monodisperse in size and uniform in composition, and quantify the alloying dynamics of these NPs in H2 and O2 under isothermal conditions. By extracting the alloying kinetics from in situ TEM measurements, we show that the alloying behavior in Au-Pd NPs can be described by a numerical diffusion model based on Fick's second law. Overall, our results indicate that exposure to reactive gasses strongly affects the surface composition and surface alloying kinetics, but has a smaller effect on the alloying dynamics of the nanoparticle bulk. Both our in situ methodology as well as the quantitative insights on restructuring phenomena can be extended to a wider range of bimetallic nanoparticle systems and are relevant in understanding the behavior of nanoparticle catalysts under operating conditions.

Direct bottom-up high pressure high temperature (BU_HPHT) synthesis of nanodiamonds (NDs) from organic precursors excels in the ability to control the size of the resulting BU_HPHT NDs via the temperature of the synthesis. Here we investigated size-dependent thermal, colloidal, and structural properties of the BU_HPHT NDs and focused on the transition in morphology and properties occurring at around 900 °C (≈2 nm). Using transmission electron microscopy, small angle X-ray scattering and atomic force microscopy we show that the sub-900 °C samples (<2 nm NDs) do not have nanoparticle character but 2D platelet morphology with sub-nm unit thickness. Correspondingly, sub-900 °C samples (<2 nm NDs) have a negative zeta potential and hydrophobic character and should be considered as a form of a molecular diamond. The above-900C (>2 nm NDs) samples have nanocrystalline character, positive zeta potential and are dispersible in water similarly to other types of hydrogenated NDs. By in situ Raman spectroscopy experiments, we show that the transition is also related to the structural instability of the oxidized sub-2 nm BU_HPHT NDs.

Superparamagnetic iron oxide nanoparticles (SPION) have received immense interest for biomedical applications, with the first clinical application as negative contrast agent in magnetic resonance imaging (MRI). However, the first generation MRI contrast agents with dextran-enwrapped, polydisperse iron oxide nanoparticle clusters are limited to imaging of the liver and spleen; this is related to their poor colloidal stability in biological media and inability to evade clearance by the reticuloendothelial system. We investigate the qualitatively different performance of a new generation of individually PEG-grafted core–shell SPION in terms of relaxivity and cell uptake and compare them to benchmark iron oxide contrast agents. These PEG-grafted SPION uniquely enable relaxivity measurements in aqueous suspension without aggregation even at 9.4 T magnetic fields due to their extraordinary colloidal stability. This allows for determination of the size-dependent scaling of relaxivity, which is shown to follow a d2 dependence for identical core–shell structures. The here introduced core–shell SPION with ∼15 nm core diameter yield a higher R2 relaxivity than previous clinically used contrast agents as well as previous generations of individually stabilized SPION. The colloidal stability extends to control over evasion of macrophage clearance and stimulated uptake by SPION functionalized with protein ligands, which is a key requirement for targeted MRI.

No abstract available

Spinel cobalt(ii,iii) oxide (Co3O4) represents a p-type semiconductor exhibiting promising functional properties in view of applications in a broad range of technological fields including magnetic materials and gas sensors as well as sustainable energy conversion systems based on photo- and electrocatalytic water splitting. Due to their high specific surface area, nanoparticle-based structures appear particularly promising for such applications. However, precise control over the diameter and the particle size distribution is required to achieve reproducible size-dependent properties. We herein introduce a synthetic strategy based on the decomposition of hydroxide precursors for the size-controlled preparation of purified Co3O4 nanoparticles with narrow size distributions adjustable in the range between 3–13 nm. The particles exhibit excellent colloidal stability. Their dispersibility in diverse organic solvents further facilitates processing (i.e. ligand exchange) and opens exciting perspectives for controlled self-assembly of the largely isometric primary particles into mesoscale structures. In view of potential applications, functional properties including absorption characteristics and electrocatalytic activity were probed by UV-Vis spectroscopy and cyclic voltammetry, respectively. In these experiments, low amounts of dispersed Co3O4 particles demonstrate strong light absorbance across the entire visible range and immobilized nanoparticles exhibit a comparably low overpotential towards the oxygen evolution reaction in electrocatalytic water splitting.

Materials for studying biological interactions and for alternative energy applications are continuously under development. Semiconductor quantum dots are a major part of this landscape due to their tunable optoelectronic properties. Size-dependent quantum confinement effects have been utilized to create materials with tunable bandgaps and Auger recombination rates. Other mechanisms of electronic structural control are under investigation as not all of a material's characteristics are affected by quantum confinement. Demonstrated here is a new structure-property concept that imparts the ability to spatially localize electrons or holes within a core/shell heterostructure by tuning the charge carrier's kinetic energy on a parabolic potential energy surface. This charge carrier separation results in extended radiative lifetimes and in continuous emission at the single-nanoparticle level. These properties enable new applications for optics, facilitate novel approaches such as time-gated single-particle imaging, and create inroads for the development of other new advanced materials.

No abstract available

Gold nanoparticles (AuNPs) are currently under intense investigation for biomedical and biotechnology applications, thanks to their ease in preparation, stability, biocompatibility, multiple surface functionalities, and size-dependent optical properties. The most commonly used method for AuNP synthesis in aqueous solution is the reduction of tetrachloroauric acid (HAuCl4) with trisodium citrate. We have observed variations in the pH and in the concentration of the gold colloidal suspension synthesized under standard conditions, verifying a reduction in the reaction yield by around 46% from pH 5.3 (2.4 nM) to pH 4.7 (1.29 nM). Citrate-capped AuNPs were characterized by UV-visible spectroscopy, TEM, EDS, and zeta-potential measurements, revealing a linear correlation between pH and the concentration of the generated AuNPs. This result can be attributed to the adverse effect of protons both on citrate oxidation and on citrate adsorption onto the gold surface, which is required to form the stabilization layer. Overall, this study provides insight into the effect of the pH over the synthesis performance of the method, which would be of particular interest from the point of view of large-scale manufacturing processes.

Colloidal lead halide perovskite nanocrystals are of interest as photoluminescent quantum dots (QDs) whose properties depend on the size and shape. They are normally synthesized on subsecond time scales through hard-to-control ionic metathesis reactions. We report a room-temperature synthesis of monodisperse, isolable, spheroidal APbBr3 QDs (“A” indicates cesium, formamidinium, and methylammonium) that are size tunable from 3 to >13 nanometers. The kinetics of both nucleation and growth are temporally separated and substantially slowed down by the intricate equilibrium between the precursor (PbBr2) and the A[PbBr3] solute, with the latter serving as a monomer. QDs of all these compositions exhibit up to four excitonic transitions in their linear absorption spectra, and we demonstrate that the size-dependent confinement energy for all transitions is independent of the A-site cation. Description Slowing nanoparticle growth Inorganic materials with more covalent bonding, such as cadmium selenide, form uniform nanoparticles under fast growth conditions, but perovskites such as cesium lead bromide (CsPbBr3) are more ionic and grow rapidly to form larger nanoparticles. Akkerman et al. controlled the nanoparticles’ growth kinetics by using trioctylphosphine oxide, which solubilized the PbBr2 precursor, bound to the cation-[PbBr3] monomer (solute), and weakly coordinated to the crystal nuclei surfaces. Nanoparticles with diameters from 3 to 13 nanometers were stabilized and isolated in high yield with lecithin, a long-chain zwitterion. Four well-resolved excitonic transitions with size-dependent confinement energies were seen for cesium as well as organic cations. —PDS Monodisperse lead-halide perovskite nanocrystals are synthesized through slow and temporally separated nucleation and growth.

Modification of the size and phase composition of magnetic oxide nanomaterials dispersed in liquids by laser synthesis and processing of colloids has high implications for applications in biomedicine, catalysis and for nanoparticle-polymer composites. Controlling these properties for ternary oxides, however, is challenging with typical additives like salts and ligands and can lead to unwanted byproducts and various phases. In our study, we demonstrate how additive-free pulsed laser post-processing (LPP) of colloidal yttrium iron oxide nanoparticles using high repetition rates and power at 355 nm laser wavelength can be used for phase transformation and phase purification of the garnet structure by variation of the laser fluence as well as the applied energy dose. Furthermore, LPP allows particle size modification between 5 nm (ps laser) and 20 nm (ns laser) and significant increase of the monodispersity. Resulting colloidal nanoparticles are investigated regarding their size, structure and temperature-dependent magnetic properties.

Iron oxide nanocubes (IONCs) are among the most promising materials in magnetic hyperthermia (MHT) for tumor therapy as they can efficiently convert magnetic energy into heat under alternating magnetic field (AMF). Conventional IONCs syntheses are based on thermal decomposition methods, limited by the long reaction time (hours) and milligram‐scale production; while, solvothermal methods produce gram‐scale amount of high quality IONCs, but, reaction times are of the orders of hours. In this work, a microwave‐assisted route to shape‐control IONCs in which the reaction time is reduced to minutes while achieving a high iron conversion yield up to 80% is reported. The size of the IONCs (range 13–30 nm) is coarse‐tuned by adjusting the amount of benzaldehyde ligand, while fine‐size tuning is achieved by changing temperature and minute‐reaction time. IONCs exhibit superparamagnetic behavior at 298 K with saturation magnetization over 80 emu gIONC−1 and possess high specific absorption rate values (SAR) up to 400 W gFe−1 at clinical AMF conditions. These results mark a milestone for rapid synthesis of IONCs at high yield conversion of well‐defined size and shape nanocubes with benchmark MHT heat performance while using a fast route, with limited energy consumption which makes this method greener and cheaper than previous ones.

The precise control of size and morphology of photocatalysts through solvothermal methods is a challenge in the basic research of 3‐D titanium dioxide (TiO2) hierarchical structures. This study utilizes the solvothermal method to synthesize N‐involved TiO2 nanoflowers with nanosheet‐assembled structures ranging from microscale (1.3 µm ± 0.2 µm) to nanoscale (200 nm ± 50 nm), achieved by varying the volume fraction (percentage by volume, vol%) of N‐N‐dimethylformamide (DMF) from 0% to 75% in a mixed solution of DMF and isopropanol (IPA). The synthesized TiO2:VFDMF = 0–75% catalyst exhibits good monodispersity and uniform particle size. With increasing DMF volume percentage, the size of TiO2:VFDMF = 0–75% decreased regularly, and the number of nanosheets constructed with a single TiO2:VFDMF = 0–75% particle decreased without any stacking or reassembly occurring. This study monitors the solvothermal processes of DMF 5% and DMF 75%, revealing the changing rules of nanoparticle size and morphology. Furthermore, the photocatalytic degradation of methyl orange shows that TiO2:VFDMF = 50% and TiO2:VFDMF = 75% are structurally stable and exhibit good photocatalytic activity without any noble metal doping. The degradation efficiency reaches 99.9%, and after repeated use, the catalysts demonstrate excellent degradation performance.

Synthesizing 2D nanosheets in a controlled and scalable manner remains a significant challenge. Here, a nanoconfined solvothermal synthesis is presented of metallic phase MoS2 (1T-MoS2) monolayers at kilogram scale. The MoS2 nanosheets exhibit a remarkably high monolayer ratio of 97%, a 1T content of ≈89%, and a well-defined average lateral size ranging from ≈100 nm to 1.0 µm, with a narrow size distribution. Moreover, these nanosheets possesses abundant surface defects, and the defect density can be regulated in situ through changing the reaction conditions. Intriguingly, the monolayer MoS2 nanosheets demonstrate good dispersibility and high stability in various solvents, including water, ethylene glycol, dimethyl formamide and others, with a high concentration of up to 1.0 mg mL-1. They are also proven to be high-performance electrocatalysts for the hydrogen evolution reaction, exhibiting an overpotential of 315 mV at an industrial current density of 1000 mA cm-2 and maintaining constant current densities of 500 mA cm-2 for up to 100 h, surpassing the performance of the commercial 20 wt.% Pt/C. Our strategy represents a significant advancement in the controlled synthesis of monolayer MoS2 at scale, providing a promising avenue for the practical application of 2D materials.

No abstract available

Barium titanate (BaTiO3) is a perovskite material with remarkable dielectric, ferroelectric, and piezoelectric properties, making it valuable in biomedical and functional devices. Its performance depends on the crystal structure, phase purity, and particle size. Conventional synthesis methods are energy-intensive and less scalable. Microwave-assisted solvothermal synthesis provides a more efficient and scalable alternative, enabling better control over particle characteristics. In this work, BaTiO3 nanoparticles (BTNPs) were prepared using the microwave-assisted solvothermal approach to examine how the reaction time affects their structural and functional behaviour. Detailed characterization revealed that the sample synthesized within 30 minutes achieved the highest crystallinity and the lowest defect density. This sample also exhibited fewer surface-bound organic residues, mainly oxygen-bound metal precursors, compared to other samples. Morphological analysis revealed that the 30 minute synthesis yielded smaller, well-crystallized particles, whereas extending the reaction time led to agglomeration. These observations were further supported by surface potential measurements, which indicated improved colloidal stability. Overall, 30 minutes was identified as the optimal synthesis time, producing BTNPs with superior crystallinity, phase purity, and functional properties. This study underscores the microwave-assisted solvothermal approach as a rapid, energy-efficient, and scalable method to produce high-quality BTNPs for applications in the dielectric, optoelectronic, and biomedical fields.

NiFe‐based MIL‐55 metal‐organic frameworks (MOFs) face challenges in achieving atomically precise composition and reliable methods for uniform growth. This study addresses these challenges by applying a slow evaporation crystallization technique to crude colloidal MIL‐55 products from hydrothermal synthesis, resulting in highly uniform, hexagonal pyramid‐shaped NiFe‐MIL‐55 nanorods (NRs). In contrast, isolating MIL‐55 through antisolvent precipitation leads to irregular shapes, highlighting the critical role of the crystallization method. This shape control enables single‐particle analysis, revealing tunable atomic compositions ranging from Ni 1 Fe 9 to Ni 9 Fe 1 by adjusting the Ni 2+ /Fe 3+ precursor ratios. A volcano‐type morphology plot illustrates the role of the Ni‐BDC framework in shape control, where Ni 4 Fe 6 to Ni 8 Fe 2 compositions produce uniform NRs, whereas others yield mixed or irregular morphologies. The electrocatalytic oxygen evolution reaction (OER) and supercapacitor performances of these NRs were evaluated, with Ni 7 Fe 3 ‐MIL‐55 showing the best OER performance, including a low overpotential of 230 mV at 10 mA cm −2 and a Tafel slope of 64 mV dec −1 . It also demonstrates excellent stability, retaining 82% of its OER activity over 50 h, as well as superior supercapacitor performance (571 F g −1 at 1 A g −1 ), making it a promising dual‐function material. Density functional theory (DFT) calculations reveal that Ni 7 Fe 3 has the lowest limiting potential (0.52 V) compared to its single‐metal counterparts, explaining its enhanced OER activity. This work provides a strategy for atomically precise MOF nanostructure design, offering valuable insights into electrocatalytic behavior and guiding the development of materials for renewable‐energy technologies.

No abstract available

No abstract available

Metal–Organic Layers (MOLs), 2D analogs of Metal–Organic Frameworks (MOFs), feature monolayer structures with the potential for various applications. Controlling the lateral size of MOLs is essential for enhancing their dispersibility in solvents and optimizing performance. However, reducing lateral dimensions while preserving monolayer thickness presents a challenge due to the precise conditions required for monolayer formation. This study utilizes a time‐resolved solvothermal synthesis method, employing flow chemistry to adjust reaction conditions dynamically during different stages of MOL growth. Fast nucleation is triggered initially to generate numerous nuclei, followed by a shift to slower growth rates, limiting further expansion and preventing the formation of amorphous structures. This approach effectively refines the lateral dimensions of nano‐MOLs while maintaining monolayer integrity. The reduction in lateral dimensions has a direct effect on improving catalytic performance, demonstrating the potential for fine‐tuned nanosized MOLs in advanced applications.

Cesium tungsten bronzes (CsxWO3), as functional materials with excellent near-infrared shielding properties, demonstrate significant potential for applications in smart windows. However, traditional synthesis methods, such as solid-state reactions and solvothermal/hydrothermal approaches, typically require harsh conditions, including high temperatures (above 200 °C), high pressure, inert atmospheres, or prolonged reaction times. In this study, we propose an optimized microwave-assisted solvothermal synthesis strategy that significantly reduces the severity of reaction conditions through precise parameter control. When benzyl alcohol was employed as the solvent, CsxWO3 nanoparticles could be rapidly synthesized within a relatively short duration of 15 min at 180 °C, or alternatively obtained through 2 h at a low temperature of 140 °C. However, when anhydrous ethanol, which is cost-effective and environmentally friendly, was substituted for benzyl alcohol, successful synthesis was also achieved at 140 °C in 2 h. This method overcomes the limitations of traditional high-pressure reaction systems, achieving efficient crystallization under low-temperature and ambient-pressure conditions while eliminating safety hazards and significantly improving energy efficiency. The resulting materials retain excellent near-infrared shielding performance and visible-light transparency, providing an innovative solution for the safe, rapid, and controllable synthesis of functional nanomaterials.

Tb3+-doped GdPO4·H2O phosphors were synthesized with wire-, rod-, and particle-like morphologies using a solvothermal method. This was achieved by varying the reaction solvent between diethylene glycol (DEG) and polyethylene glycol (PEG) of different molecular weights. The crystal structure, morphology, and photoluminescence (PL) properties were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and PL spectroscopy. The emission spectra showed the characteristic green luminescence of Tb³⁺ ions, with transition from the 5D4 → 7Fj (J = 6, 5, 4, 3) at 489, 543, 586, and 620 nm, respectively. Systematic analysis revealed a strong correlation between material morphology, crystal structure, and luminescence efficiency. The sample with a nanoparticle morphology, synthesized at 100 °C in a PEG 8000 medium, exhibited the highest PL intensity. It displayed a dominant green emission at 543 nm (5D4 → 7F5) and sharp, well-defined emission bands. These findings confirm that a solvent-mediated morphology control strategy is effective for optimizing the luminescence performance of GdPO4-based phosphors.

In this work, the self-assembled SrTiO3 (STO) microstructures were synthesized via a facile one-step solvothermal method. As the solvothermal temperature increased from 140 °C to 200 °C, the STO changed from a flower-like architecture to finally an irregularly aggregated flake-like morphology. The photocatalytic performance of as-synthesized samples was assessed through the degradation of rhodamine B (RhB) and malachite green (MG) under simulated solar irradiation. The results indicated that the photocatalytic performance of STO samples depended on their morphology, in which the hierarchical flower-like STO synthesized at 160 °C demonstrated the highest photoactivities. The photocatalytic enhancement of STO-160 was benefited from its large surface area and mesoporous configuration, hence facilitating the presence of more reactive species and accelerating the charge separation. Moreover, the real-world practicality of STO-160 photocatalysis was examined via the real printed ink wastewater-containing RhB and MG treatment. The phytotoxicity analyses demonstrated that the photocatalytically treated wastewater increased the germination of mung bean seeds, and the good reusability of synthesized STO-160 in photodegradation reaction also promoted its application in practical scenarios. This work highlights the promising potential of tailored STO microstructures for effective environmental remediation applications.

To improve thermoelectric performance of materials, the utilization of low-dimensional materials with a multi-alloy system is a promising approach. We report on the enhanced thermoelectric properties of n-type Bi2(SexTe1−x)3 nanoplates using solvothermal synthesis by tuning the composition of selenium (Se). Variation of the Se composition within nanoplates is demonstrated using X-ray diffraction and electron probe microanalysis. The calculated lattice parameters closely followed Vegard’s law. However, when the Se composition was extremely high, an impurity phase was observed. At a reduced Se composition, regular-hexagonal-shaped nanoplates with a size of approximately 500 nm were produced. When the Se composition was increased, the shape distribution became random with sizes more than 5 μm. To measure the thermoelectric properties, nanoplate thin films (NPTs) were formed on a flexible substrate using drop-casting, followed by thermal annealing. The resulting NPTs sufficiently adhered to the substrate during the bending condition. The electrical conductivity of the NPTs increased with an increase in the Se composition, but it rapidly decreased at an extremely high Se composition because of the presence of the impurity phase. As a result, the Bi2(SexTe1−x)3 NPTs exhibited the highest power factor of 4.1 μW/(cm∙K2) at a Se composition of x = 0.75. Therefore, it was demonstrated that the thermoelectric performance of Bi2(SexTe1−x)3 nanoplates can be improved by tuning the Se composition.

Halide perovskites have attracted enormous attention due to their potential applications in optoelectronics and photocatalysis. However, concerns over their instability, toxicity, and unsatisfactory efficiency have necessitated the development of lead-free all-inorganic halide perovskites. A major challenge in designing efficient halide perovskites for practical applications is the lack of effective methods for producing nanocrystals with precise size and shape control. In this work, a layered perovskite, Cs4ZnSb2Cl12 (CZS), is found from calculations to exhibit size- and facet-dependent optoelectronic properties in the nanoscale, and thus, a colloidal method is used to synthesize the CZS nanoparticles with size-tunable morphologies: zero- (nanodots), one- (nanowires and nanorods), two- (nanoplates), and three-dimensional (nanopolyhedra). The growth kinetics of the CZS nanostructures, along with the effects of surface ligands, reaction temperature, and time were investigated. The optoelectronic properties of the nanocrystals varied with size due to quantum confinement effects and with shape due to anisotropy within the crystals and the exposure of specific facets. These properties could be modulated to enhance the visible-light photocatalytic performance for toluene oxidation. In particular, the 9.7 nm CZS nanoplates displayed a toluene to benzaldehyde conversion rate of 1893 μmol g-1 h-1 (95% selectivity), 500 times higher than the bulk synthesized CZS, and comparable with the reported photocatalysts. This study demonstrates the integration of theoretical calculations and synthesis, revealing an approach to the design and fabrication of novel, high-performance colloidal perovskite nanocrystals for optoelectronic and photocatalytic applications.

Over the past few decades, battery research has increasingly focused on titanium dioxide (TiO2) and manganese dioxide (MnO2), with TiO2 commonly used as an anode material and MnO2 as a cathode, due to their stability, abundance, and low cost. In this study, a novel TiO2-based material doped with high manganese (Mn) content was synthesized via a high-temperature solution-phase synthesis method using a single-source precursor for application in lithium-ion batteries (LIBs). The synthesis was conducted under controlled conditions, achieving high Mn n+ cation doping levels of up to 20–25 mol %, leading to previously unreported changes in the material’s electrochemical performance. A temperature-dependent phase transformation from anatase to rutile was observed. Samples with 5 mol %, 20 mol %, and 50 mol % Mn n+-ion doping were prepared and investigated for their structural, morphological, and electrochemical characteristics. Characterization techniques included X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). The doped materials exhibited properties distinct from those of pure TiO2 and pure MnO2, indicating effective Mn incorporation into the TiO2 lattice. This study highlights the potential of high-Mn-content TiO2-based materials as next-generation anode candidates for LIBs while also revealing the performance limitations associated with excessive Mn doping. The resulting insights into the chemistry of Ti–Mn mixed oxide anodes demonstrate the strong link between molecular precursor design and the resulting phase composition and structure. The latter is directly related to the electrochemical performance, offering a better understanding for future design and engineering of next-generation mixed oxide electrodes.

In this work, Ag nanoparticles (NPs) were fabricated by thermal decomposition of silver nitrate in organic solvents in the presence of sodium oleate (SOA) and 1-octadecanol (OCD-ol). The effects of different solvents and concentrations of OCD-ol on the morphology and properties of the Ag nanomaterials were investigated in detail. The structural analysis of the Ag nanomaterials showed good crystallinity. The TEM images of the samples showed that with the change in the fabrication conditions, different sizes and shapes of Ag nanomaterials were formed. The surface plasmon resonance (SPR) properties of the  Ag NPs were influenced by their size and shape. The as-synthesized Ag NPs have potential applications in biomedical, catalysis, or electronics.

No abstract available

No abstract available

This study explores the synthesis and characterization of ZnO particles with varying morphologies—triangular, spherical, and urchin‐like—that were produced through a simple, solvothermal process. The morphology, surface area, and photocatalytic performance of the ZnO particles could be customized by meticulously regulating the synthesis parameters, particularly the temperature and solvent. The findings indicated that all samples crystallized as pure wurtzite ZnO with a uniform crystallite size of 34.7 ± 1.8 nm and energy band gap of 3.29 eV. The spherical E‐200 particles, which exhibit the highest photocatalytic efficiency, achieved an average of 25.27 ± 5.88% methylene blue (MB) degradation after 24 h. These particles were distinguished by a significant surface area of 30.56 m2/g and an average pore size of 45 nm. Furthermore, all ZnO samples exhibited a significant adsorption capacity (≤ 20%) for MB under dark condition, underscoring their potential as effective adsorbents for environmental pollutants. These results emphasize the significance of precise synthesis and morphology control in the optimization of functional properties of ZnO for environmental remediation applications.

Gold nanoparticles have unique properties that are highly dependent on their shape and size. Synthetic methods that enable precise control over nanoparticle morphology currently require shape‐directing agents such as surfactants or polymers that force growth in a particular direction by adsorbing to specific crystal facets. These auxiliary reagents passivate the nanoparticles' surface, and thus decrease their performance in applications like catalysis and surface‐enhanced Raman scattering. Here, a surfactant‐ and polymer‐free approach to achieving high‐performance gold nanoparticles is reported. A theoretical framework to elucidate the growth mechanism of nanoparticles in surfactant‐free media is developed and it is applied to identify strategies for shape‐controlled syntheses. Using the results of the analyses, a simple, green‐chemistry synthesis of the four most commonly used morphologies: nanostars, nanospheres, nanorods, and nanoplates is designed. The nanoparticles synthesized by this method outperform analogous particles with surfactant and polymer coatings in both catalysis and surface‐enhanced Raman scattering.

Shape-and size-controlled synthesis of nanomaterials has been a long-term aim and challenge of modern nanotechnology. Despite many synthesis methods are still mainly focused on the production of near-spherical NPs, a number of emerging applications require nanomaterials of nonspherical shape and developed surface, which determine the functional performance of nanostructured devices. Laser ablation in liquids has been demonstrated as a clean, simple, and versatile NP synthesis method. However, the conditions of NP formation and growth are favouring the production of spherical NPs. There are fewer studies of shape control during laser ablation. With that in mind, this perspective article represents a view on the current stage of the development of laser ablation in liquids from the perspective of shape control of the forming nanomaterials. The key parameters influencing the NP shape are highlighted, including the composition of a liquid, laser focusing conditions and introduction of external fields, and the mechanism of their impact on the conditions for anisotropic NP formation and growth. The description of the methods developed for the control over nanomaterial morphology is summarized by the vision of the current challenges and development routes of laser ablation in liquids.

Designing semiconductor photocatalysts with unique structures can improve the transfer efficiency of solar energy to hydrogen (H2). In this study, a dual modification method of element doping and morphological control was used. The Mn-doped hollow octahedron ZnIn2S4 (ZHO-Mn) was synthesized by a simple one-pot solvothermal method using the octahedral Mn-based metal-organic framework (Mn-MOF) as a template. Experiments and theoretical calculations show that the ZHO-Mn has additional active sites, strong light absorption ability and good photoelectric performance. The H2 production performance of optimized ZHO-Mn10 was the best (11.9 mmol  h-1 g-1), which was 7.4 times that of monomer ZnIn2S4 (1.6 mmol  h-1 g-1). This study provides a new one-step method for the dual control of doping and morphology of ZnIn2S4 photocatalyst.

Nickel–Cobalt–Aluminum (NCA) cathode materials for lithium-ion batteries (LIBs) are conventionally synthesized by chemical co-precipitation. However, the co-precipitation of Ni2+, Co2+, and Al3+ is difficult to control because the three ions have different solubility product constants. This study proposes a new synthetic route of NCA, which allows fabrication of fine and well-constructed NCA cathode materials by a high temperature solid-state reaction assisted by a fast solvothermal process. The capacity of the LiNi0.88Co0.09Al0.03O2 as-synthesized by the solvothermal method was 154.6 mA h g−1 at 55 °C after 100 cycles, corresponding to 75.93% retention. In comparison, NCA prepared by the co-precipitation method delivered only 130.3 mA h g−1 after 100 cycles, with a retention of 63.31%. Therefore, the fast solvothermal process-assisted high temperature solid-state method is a promising candidate for synthesizing high-performance NCA cathode materials.

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Herein, mesoporous tin dioxide materials with distinct structures (SnO2 microflowers and SnO2 microsheets) were, respectively, prepared via a citrate-mediated solvothermal route along with a post-annealing treatment in air. Electrochemical tests revealed a typical battery-type charge storage behavior of SnO2 materials. Attributing to the 3D hierarchical flower-like structure and its good conductivity, the SnO2 microflowers possessed a specific capacity of 177.2 C g-1, slightly greater than 159.0 C g-1 achieved by SnO2 microsheets under 1 A g-1. When assembled into hybrid supercapacitors (HSCs) utilizing activated carbon (AC) as an anode, the SnO2 microflowers//AC HSC device delivered a high energy density (ED) of 29.5 W h kg-1 at 883.9 W kg-1, surpassing SnO2 microsheets//AC HSC (26.9 W h kg-1 at 881.7 W kg-1). Furthermore, both SnO2//AC HSCs exhibited long-term stability, showing 113.2% (SnO2 microflowers//AC) and 106.4% (SnO2 microsheets//AC) capacity retention over 5000 cycles. Notably, this synthesis strategy achieves facile morphological control and improved electrochemical properties of SnO2 materials by adjusting the sodium citrate amount. These results indicate that SnO2 microflowers and SnO2 microsheets are attractive candidates for high-performance HSC assembly. Furthermore, this cost-effective approach can provide a reference for synthesizing other advanced metal oxide-based electrode materials.

Despite the structural and electrochemical advantages of LiFePO4 (LFP) as a cathode material, the solid-state reaction commonly used as a method to produce it at the industrial level has known disadvantages associated with high energy and fossil fuel consumption. On the other hand, solution-based synthesis methods present a more efficient way to produce LFP and have advantages such as controlled crystal growth, homogeneous morphology, and better control of pollutant emissions because the reaction occurs within a closed system. From an environmental point of view, different impacts associated with each synthesis method have not been studied extensively. The use of less polluting precursors during synthesis, as well as efficient use of energy and water, can provide new insights into the advantages of each cathode material for more environmentally friendly batteries. In this work, a solvothermal method is compared to a solid-state synthesis method commonly used to elaborate LFPs at the commercial level in order to evaluate differences in the environmental impacts of both processes. The solvothermal method used was developed considering the reutilization of solvent, water reflux, and a low thermal treatment to reduce pollutant emissions. As a result, a single high crystallinity olivine phase LFP was successfully synthesized. The use of ethylene glycol (EG) as a reaction medium enabled the formation of crystalline LFP at a low temperature (600 °C) with a nano-plate-like shape. The developed synthesis method was evaluated using life cycle analysis (LCA) to compare its environmental impact against the conventional production method. LCA demonstrated that the alternative green synthesis process represents 60% and 45% of the Resource Depletion impact category (water and fossil fuels, respectively) of the conventional method. At the same time, in the Climate change and Particular matter impact categories, the values correspond to 49 and 38% of the conventional method, respectively.

In this study, we synthesized four novel mixed‐ligand metal‐organic frameworks (MOFs): MOF@1 [Co(H 2 BDC‐N 2 H 3 )(BPY)], MOF@2 [Co(H 2 BDC‐N 2 H 3 )(BPY)@(SA)], MOF@3 [Ni(H 2 BDC‐N 2 H 3 )(BPY)], and MOF@4 [Ni(H 2 BDC‐N 2 H 3 )(BPY)@(SA)] via one pot solvothermal technique at 150 °C. The resultant MOFs were examined using FT‐IR, PXRD, and SEM to confirm their structural integrity and morphological features. Biological tests demonstrated potential antibacterial activity, particularly from MOF@4. In antibacterial experiments, MOF@4 revealed a considerable zone of inhibition (13 mm) at a dose of 100 µg against Staphylococcus aureus (Gram‐positive) and Escherichia coli (Gram‐negative), using + ampicillin as the standard control. In antifungal experiments against Candida albicans , MOF@4 had the most significant antifungal activity among the synthesized MOFs, with a 15 mm inhibition zone at the same concentration, surpassing fluconazole. MOF@4 had the highest adsorption capability, with a maximum capacity of 86.9 mg/g for MO and 68.02 mg/g for MB. The remarkable adsorption capacity of MOF@4 positions it as a viable choice for wastewater treatment, surpassing its competitors: MOF@1 (25.8 mg/g for MO; 83.3 mg/g for MB), MOF@2 (58.1 mg/g for MO; 33.4 mg/g for MB), and MOF@3 (67.2 mg/g for MO; 40.4 mg/g for MB). These findings establish a basis for additional research aimed at improving MOF structures for multifunctional applications.

The design of a highly active Fe-supported catalyst with the optimum particle and pore size, dispersion, loading, and stability is essential for obtaining the desired product selectivity. This study employed a solvothermal method to prepare two Fe-MIL-88B metal–organic framework (MOF)-derived catalysts using triethylamine (TEA) or NaOH as deprotonation catalysts. The catalysts were analyzed using X-ray diffraction, N2-physisorption, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, H2 temperature-programed reduction, and thermogravimetric analysis and were evaluated for the Fischer–Tropsch synthesis performance. It was evident that the catalyst preparation in the presence of TEA produces a higher MOF yield and smaller crystal size than those produced using NaOH. The pyrolysis of MOFs yielded catalysts with different Fe particle sizes of 6 and 35 nm for the preparation in the presence of TEA and NaOH, respectively. Also, both types of catalysts exhibited a high Fe loading (50%) and good stability after 100 h reaction time. The smaller particle size TEA catalyst showed higher activity and higher olefin yield, with 94% CO conversion and a higher olefin yield of 24% at a lower reaction temperature of 280 °C and 20 bar at H2/CO = 1. Moreover, the smaller particle size TEA catalyst exhibited higher Fe time yield and CH4 selectivity but with lower chain growth probability (α) and C5+ selectivity.

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Bismuth oxychloride photocatalysts were obtained using solvothermal synthesis and different additives (CTAB—cetyltrimethylammonium bromide, CTAC—cetyltrimethylammonium chloride, PVP–polyvinylpyrrolidone, SDS–sodium dodecylsulphate, U—urea and TU—thiourea). The effect of the previously mentioned compounds was analyzed applying structural (primary crystallite size, crystal phase composition, etc.), morphological (particle geometry), optical (band gap energy) parameters, surface related properties (surface atoms’ oxidation states), and the resulted photocatalytic activity. A strong dependency was found between the surface tension of the synthesis solutions and the overall morpho-structural parameters. The main finding was that the characteristics of the semiconductors can be tuned by modifying the surface tension of the synthesis mixture. It was observed after the photocatalytic degradation, that the white semiconductor turned to grey. Furthermore, we attempted to explain the gray color of BiOCl catalysts after the photocatalytic decompositions by Raman and XPS studies.

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Fabricating covalent organic frameworks with different morphologies based on the same structural motifs is both interesting and challenging. Here, a TTA-TFP-COF was synthesized by both solvothermal and room temperature methods, with 2,4,6-Tris(4-aminophenyl)-1,3,5-triazine (TTA) and 1,3,5-tris(4-formylphenyl)-benzene (TFP) as raw material. Using different synthesis conditions and adding aniline and benzaldehyde as regulators in the synthesis process, we found that these processes could slow down the reaction speed, increase the exchange and metathesis reactions of dynamic reversible reactions, and improve the reversibility of the reaction system. Thus, controllable synthesis of TTA-TFP-COF with different morphologies, including micro-particles, hollow tubes with controllable diameters, and micro-flowers was achieved. Our further study found that metal ions, Fe3+ and Cr3+ ions, could coordinate with N and O in TTA-TFP-COF and partially destroy the structure of TTA-TFP-COF. The particle size of the TTA-TFP-COF became smaller, thus resulting in the decrease of the light scattering intensity of the COF. An excellent linear relationship exists between the light scattering changes (ΔI) and metal ions concentration (c) from 2.0 to 350.0 μM for Fe3+ and 40.0-800.0 μM for Cr3+, respectively. Thus, rapid and selective analytical methods for detecting metal ions were developed by TTA-TFP-COF here.

Hydrogen peroxide (H2O2) is one of the most valuable clean energy sources with a rapidly growing requirement in industry and daily life. The direct synthesis of H2O2 from hydrogen and oxygen is considered to be an economical and environmentally friendly manufacturing route to replace the traditional anthraquinone method, although it remains a formidable challenge owing to low H2O2 selectivity and production. Here, we report a catalyst consisting of Pd(111) nanocrystals on TiO2 modified with single Pt atoms (Pt1Pd(111)/TiO2), which displays outstanding reactivity, producing 1921.3 μmol of H2O2, a H2 conversion of 62.2% and H2O2 selectivity of 80.3% over 30 min. Kinetic and isotope experiments confirm that the extraordinary catalytic properties are due to stronger H2 activation (the rate-determining step). DFT calculations confirm that Pt1Pd(111) exhibits lower energy barriers for H2 dissociation and two-step O2 hydrogenation, but higher energy barriers for side reactions than Pt1Pd(100), demonstrating clear facet dependence and resulting in greater selectivity and amount of H2O2 produced.

Photothermal CO2 hydrogenation with green H2 for conversion into fuels or chemicals is a promising technology for efficient CO2 conversion with low energy input. However, low catalytic activity and selectivity are one of the difficulties in photothermal catalysis, so it is crucial to develop photothermal catalysts with high catalytic activity. By employing crystalline surface engineering, specific highly active crystalline surfaces can be exposed, which have more active sites and can improve the photothermal performance of the catalysts to some extent. Based on this, two kinds of Co3O4 nanocrystals with exposed different facets are synthesized via the hydrothermal method, and the facet-dependent reactivity in photothermal CO2 hydrogenation is explored. The results showed that the Co3O4 nanocubes with exposed (001) facets presented the CH4 yield of 11.00 mmol h-1 with 61.06% CO2 conversion and 80% CH4 selectivity, which is ≈39% higher than the yield of Co3O4 octahedrons enclosed by (111) facets. Co3O4 with exposing only (001) facets has a higher Co2+/Co0 ratio, thus resulting in better CO2 adsorptions favoring the formic acid path to produce methane. This study provides a series of new facet-dependent photothermal catalyst designs and reveals for the first time the effect of thermal energy on catalyst conductivity.

Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds. This study provides a comprehensive analysis of the adsorption and photo‐oxidation of surface‐adsorbed acetone on three SrTiO3 morphologies: cubes (for which exclusively {100} facets are exposed), {110}‐truncated cubes, and {100}‐truncated rhombic dodecahedrons, respectively, all prepared by hydrothermal synthesis. In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy shows that cubic crystals contain a high quantity of surface –OH groups, enabling significant quantities of adsorbed acetone in the form of η1‐enolate when exposed to gas phase acetone. Contrary, {110} facets exhibit fewer surface –OH groups, resulting in relatively small quantities of adsorbed η1‐acetone, without observable quantities of enolate. Interestingly, acetate and formate signatures appear in the spectra of cubic, surface η1‐enolate containing, SrTiO3 upon illumination, while besides acetate and formate, the formation of (surface) formaldehyde was observed on truncated cubes, and dodecahedrons, by conversion of adsorbed η1‐acetone. Time‐Resolved Photoluminescence studies demonstrate that the lifetimes of photogenerated charge carriers vary with crystal morphology. The shortest carrier lifetime (τ1 = 33 ± 0.1 ps) was observed in {110}‐truncated cube SrTiO3, likely due to a relatively strong built‐in electric field promoting electron transport to {100} facets and hole transport to {110} facets. The second lifetime (τ2 = 259 ± 1 ps) was also the shortest for this morphology, possibly due to a higher amount of surface trap states. Our results demonstrate that SrTiO3 crystal morphology can be tuned to optimize performance in photocatalytic oxidation.

An innovative viscosity-dependent hydrothermal strategy is developed for the controlled synthesis of multinary titanate perovskites, specifically Na0.5Y0.39Yb0.1Er0.01TiO3. By manipulating the viscosity of the reaction solution using various stable additives in both type and quantity, we identify a critical viscosity threshold of ~100 centipoise, which is essential for producing uniform faceted particles. With sodium hydroxide as an additive, a clear morphological evolution occurs as hydroxide concentration increases, shifting from regular cubes to edge-truncated, half-corner-truncated, and fully corner-truncated cube particles. Furthermore, the inclusion of additional sodium chloride and acetate substantially increases the viscosity, facilitating the formation of uniform faceted particles with reduced sizes ranging from ~2.0 micrometers to 200 nanometers. This method is successfully applied to synthesize other uniform perovskites, including Na0.5Y0.395Yb0.1Tm0.005TiO3, Na0.5Y0.4Eu0.1TiO3, Na0.5Y0.39Yb0.1Ho0.01TiO3, and Na0.5Bi0.5TiO3. Our findings provide valuable insights into viscosity-controlled synthesis for creating multinary perovskites and enhance their potential for designing optical functional materials and advancing various applications in optical temperature sensing, anti-counterfeiting security, and fingerprint recognition.

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Iron sulfide-supported hydrochar (FeS-HTC) was synthesized via a one-pot hydrothermal process by simultaneously reacting microalgae (AG) and sewage sludge digestate (SD) biomass with iron and sulfur precursors. The effects of biomass type, iron and sulfur concentrations, and sulfur-to-iron (S/Fe) molar ratio on the iron sulfide phase formation and oxidation performance of the resulting materials were systematically investigated. X-ray diffraction (XRD) revealed that the S/Fe ratio strongly influenced iron sulfide phase formation: AG-derived FeS-HTC exhibited a phase transformation sequence from pyrrhotite (Fe1-xS) to greigite (Fe3S4) to pyrite (FeS2) as sulfur content increased, while SD-derived samples consistently formed pyrite across all conditions. Surface analysis via XPS and FT-IR confirmed the incorporation of mixed-valence and oxidized iron species (e.g., phosphoferrite and greigite) in AG samples and predominantly reduced species (e.g., pyrite) in SD samples. SEM study showed biomass-dependent morphologies, with AG producing microspheres and SD forming nanoscale particle aggregates. The FeS-HTCs exhibited strong catalytic activity in Fenton-like oxidation of methylene blue under acidic conditions. Enhanced degradation was observed at S/Fe = 4, especially in pyrite-rich samples, due to efficient Fe2+/Fe3+ cycling and hydroxyl radical generation. Notably, SD-derived FeS-HTC demonstrated faster initial reaction rates, while AG-derived samples allowed for selective synthesis of greigite at S/Fe = 3. These findings highlight the importance of biomass composition and sulfur dosage in tuning the structure and reactivity of FeS-HTCs. The materials developed in this study show strong potential for use in advanced oxidation processes for wastewater treatment and other environmental remediation applications.

Abstract A palladium (Pd)-doped rGO/ZnO nanocomposite was prepared using the hydrothermal method. The nanocomposite underwent various analytical assessments to determine its structural, optical, and morphological properties. The analytical results confirmed the successful formation of the Pd-doped rGO/ZnO composite. This composite, referred to as Pd-rGO/ZnO, was employed for the photocatalytic degradation of Coomassie Brilliant Blue R-250 (CBR) dye. The prepared photocatalyst, Pd-rGO/ZnO, exhibited a remarkable 93% efficiency in degrading CBR dye within 150 min under UV light. The enhanced photocatalytic and antibacterial activities were achieved by modifying rGO and introducing Pd, which effectively increased the reactive surface area and facilitated electron transfer. Moreover, the composite also displayed significant antibacterial activity in a dose-dependent manner. GRAPHICAL ABSTRACT Dye degradation over Pd-rGO/ZnO photocatalyst under UV light irradiation (DM – Dye molecules).

Bismuth oxyiodide (BiOI) is a promising photocatalyst for visible-light-driven environmental remediation. However, its photocatalytic efficiency is highly dependent on synthesis conditions, particularly hydrothermal temperature, which governs its structural, optical, and electronic properties. In this study, BiOI was synthesized via a hydrothermal method at temperatures of 120℃, 150℃, 180℃, and 210℃ to investigate the effect of temperature on its photocatalytic performance systematically. Comprehensive characterizations, including X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence and photocatalytic degradation studies, were conducted to analyze crystallinity, morphology, band structure and charge transfer properties. The results demonstrated that BiOI synthesized at 180℃ exhibited an optimal combination of crystallinity and particle dispersion, which enhanced charge separation and photocatalytic activity. It achieved a degradation efficiency of 94% for indigo carmine within 60 min under visible light irradiation. The bandgap energy and electronic structure of BiOI played a critical role in determining the dominant reactive species, with superoxide radicals (•O2−) being the primary contributors to indigo carmine degradation. The study provides new insights into the relationship between synthesis temperature, structural evolution, and photocatalytic efficiency, offering a scalable and effective approach for optimizing BiOI-based photocatalysts for environmental applications.

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In this study, we investigated the influence of pH on the hydrothermal synthesis of copper (II) oxide CuO nanostructures with the aim of tuning their morphology. By varying the pH of the reaction medium, we successfully produced CuO nanostructures with three distinct morphologies including nanoparticles, nanorods, and nanosheets according to the pH levels of 4, 7, and 12, respectively. The observed variations in surface morphology are attributed to fluctuations in growth rates across different crystal facets, which are influenced by the presence of intermediate species within the reaction. This report also compared the structural and optical properties of the synthesized CuO nanostructures and explored their potential for photoelectrochemical glucose sensing. Notably, CuO nanoparticles and nanorods displayed exceptional performance with calculated limits of detection of 0.69 nM and 0.61 nM, respectively. Both of these morphologies exhibited a linear response to glucose within their corresponding concentration ranges (3–20 nM and 20–150 nM). As a result, CuO nanorods appear to be a more favorable photoelectrochemical sensing method because of the large surface area as well as the lowest solution resistance in electroimpedance analysis compared to CuO nanoparticles and nanosheets forms. These findings strongly suggest the promising application of hydrothermal-synthesized CuO nanostructures for ultrasensitive photoelectrochemical glucose biosensors.

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The migration and transformation of hexavalent chromium (Cr(VI)) in the environment are regulated by pyrite (FeS2). However, variations in pyrite crystal facets influence the adsorption behavior and electron transfer between pyrite and Cr(VI), thereby impacting the Cr(VI) reduction performance. Herein, two naturally common facets of pyrite were synthesized hydrothermally to investigate the facet-dependent mechanisms of Cr(VI) reduction. The experimental results revealed that the {111} facet exhibited approximately 1.30-1.50 times higher efficiency in Cr(VI) reduction compared to the {100} facet. Surface analyses and electrochemical results indicated that {111} facet displayed a higher iron-sulfur oxidation level, which was affected by its superior electrochemical properties during the reaction with Cr(VI). Density functional theory (DFT) calculations demonstrated that the narrower band gap and lower work function on {111} facet were more favorable for the electron transfer between Fe(II) and Cr(VI). Furthermore, different adsorption configurations were observed on {100} and {111} surfaces due to the unique arrangements of Fe and S atoms. Specifically, O atoms in Cr2O72- directly bound with the S sites on {100} but the Fe sites on {111}. According to the density of states (DOS), the Fe site had better reactivity than the S site in the reaction, which appeared to be related to the fracture of S-S bonds. Additionally, the adsorption configuration of Cr2O72- on {111} surface showed a stronger adsorption energy and a more stable coordination mode, favoring subsequent Cr(VI) reduction process. These findings provide an in-depth analysis of facet-dependent mechanisms underlying Cr(VI) reduction behavior, offering new insights into studying environmental interactions between heavy metals and natural minerals.

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TiO2/MXene heterostructure has garnered significant interest as a photocatalyst due to its large surface area and efficient charge carrier separation at the interface. However, current synthesis methods produce TiO2 without clear crystal faceting and often require complicated postprocessing step, limiting its practical applications. We demonstrate a facile and controlled microwave-assisted hydrothermal synthesis for transforming multilayered Ti3CN MXene to a truncated-bipyramidal TiO2/Ti3CN heterostructure. The resulting TiO2 nanocrystals at the Ti3CN surface exhibited crystalline anatase truncated bipyramids, exposing {001} and {101} facets. We further tailored an indirect optical band gap of the TiO2/Ti3CN heterostructure in the range of 3.17–3.23 eV by varying the hydrothermal synthesis time from 15 min to 5 h at a fixed temperature of 160 °C. Efficient charge separation allowed us to decompose 97% of methylene blue (MB) within 30 min of ultraviolet (UV) light irradiation, ∼3.9-fold faster than the benchmark P25, higher than any other TiO2/MXene heterostructures. With simulated white light, we achieved over 60% efficiency of the dye decomposition within 2 h of irradiation, which resulted in 1.5-fold faster kinetics than P25. We also observed a similar excellent performance of Ti3CN-derived TiO2 in decomposing various persistent synthetic dyes, including commercial textile dye, methyl orange, and rhodamine B. In conclusion, our study provides a strategy for utilizing MXene chemical reactivity to produce highly crystalline optically active TiO2/Ti3CN heterostructure. The developed heterostructure can serve as an efficient photocatalyst for the degradation of organic pollutants.

The development of photosynthetic biohybrid systems (PBSs) integrating inorganic light absorbers with non-photosynthetic bacteria innovate wastewater valorization via organics bioconversion, yet interfacial electron transfer bottlenecks limit efficiency. To address this, we regulated crystal facet exposure ratios in cadmium sulfide/reduced graphene oxide (CdS/RGO) through hydrothermal synthesis time control, observing facet-dependent activity trends. The optimized biohybrid achieved a maximum hydrogen yield of 2195.3 μmol (233.6 µmol·g-1·h-1 over 8 h), representing a 295 % enhancement over unmodified PBSs. Density functional theory (DFT) calculations revealed that increased exposure of high-activity (103) and (112) facets correlated with reduced work function values, promoting electron emission. Synergistically combined with RGO's electron-shuttling function, this facilitated charge transfer to bacterial outer membrane proteins. These results demonstrate facet engineering as a tunable strategy for enhancing electron donation capacity in PBSs, offering design principles for biohybrid systems.

Growth of exposed crystal facets has received considerable attention because of their coordinatively unsaturated surface atoms and defect-related surface reactivities. Herein, LiFeO2 truncated octahedra exposed with 6 {100} facets and 8 {111} facets were prepared through a simple microwave-assisted hydrothermal method without using any additives, surfactants, and calcination processes. The detailed growth process revealed that the formation of LiFeO2 truncated octahedra occurred only at the optimized reaction temperature (180 °C), time (30 min), and reactant concentrations. The prepared LiFeO2 truncated octahedra showed excellent sensing responses toward aliphatic organic compounds compared to that against aromatic organic compounds and poor response to inorganic compounds. The response percentages of 150 ppm concentrations of acetone, ethanol, formaldehyde, and isopropyl alcohol are 81.84, 62.91, 62.68, and 69.41%, respectively, at a low operating temperature (100 °C). The presence of exposed facets with their coordinatively unsaturated Li/Fe surface atoms such as 5-fold {100}, 3-fold {111}, 3-fold {100}-{111}, 2-fold {111}-{111}, and 2-fold coordination with the O atom in the vertices facilitated more oxygen vacancies and led to improved surface reactivities as well as sensitivity.

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A series of samples including leaf-like and rod-like rutile TiO2 nanoparticles with various facets exposed on the surface, parallelepiped-shaped anatase nanoparticles with [111]-vertical facet exposed on the surface, irregular anatase nanoparticles as well as micro-sized six-point star-like anatase aggregates and almond-like brookite aggregates had been hydrothermally synthesized from the lepidocrocite-type layered titanate nanosheets. A systematical investigation was established to uncover the phase transition and morphological evolution from nanosheets to TiO2 polymorphs and a phase diagram was determined by adjusting the synthesis parameters of the pH value and temperature. Two kinds of mechanisms composed of dissolution-deposition process following Ostwald's ripening mechanism and in-situ topochemical conversion process following Ostwald's step rule had been proposed based on the time-dependent hydrothermal experiments. Briefly, the formation of single-crystalline rutile phase appeared only at high temperatures with very low pH values, and similarly, brookite phase strictly formed at high temperatures with very high pH value. Nevertheless, anatase phase could moderately appeared at wide range of temperatures and pH values. And the single-crystalline rutile adopted a leaf-like morphology at low temperatures with high pH values and a rod-like morphology at high temperatures with low pH values while the morphological evolution of anatase particles proceeded from irregular to parallelepiped-shaped, finally to six-point star-like morphology and the crystal size was reduced from 1000 nm to 5 nm with decreasing pH values. Meanwhile, with the prolong of the hydrothermal time, the layered titanate nanosheets first dissolved into amorphous state and further converted into small anatase nanoparticles, finally to rutile or anatase nanoparticles based on dissolution-deposition process or the {010}-faceted layered titanate structure first converted into the [111]-vertical faceted anatase nanosheets by the topochemical transformation reaction and then split into the [111]-vertical faceted anatase nanoparticles. More importantly, the mesoporous [111]-vertical faceted anatase nanoparticles exhibited enhanced photocatalytic performance compared to that of Degussa P25, which was ascribed to its superior electronic band structure and effective charge separation. The systematical investigation in this work would be significant for consummating the preparation of the TiO2 polymorphs from layered titanate nanosheets and provided some reference value and guide scheme for preparation of TiO2 nanoparticles with outstanding photocatalytic performance.

In this study, we are reporting for the first time the utilization of Solanum tuberosum tuber-driven, starch-mediated, green-hydrothermally synthesized cerium oxide nanoparticles (G-CeO2 NPs) for the antibacterial activity and photodegradation of cationic (methylene blue, MB) and anionic (methyl orange, MO) dyes separately and in combination, aimed at environmental remediation. The XRD analysis confirms the fluorite structure of G-CeO2 NPs, displaying an average crystallite size of 9.6 nm. Further, XPS confirms the existence of 24% of Ce3+ oxidation states within G-CeO2 NPs. Morphological studies through FE-SEM and TEM reveal that starch-driven OH- ion production leads to a high percentage of active crystal facets, favoring the formation of Ce3+-rich CeO2 NPs. Photocatalytic experiments conducted under UV-A illumination demonstrate the superior degradation performance of G-CeO2 NPs, with MB degradation reaching 93.4% and MO degradation at 77.2% within 90 min. This outstanding catalytic activity is attributed to the mesoporous structure (pore diameter of 5.63 nm) with a narrow band gap, a large surface area (103.38 m2g-1), and reduced charge recombination, as validated by BET, UV-visible, and electrochemical investigations. The identification of photogenerated intermediates is achieved through LCMS, while the mineralization is monitored via total organic carbon analysis. Moreover, the scavenging experiments point towards the involvement of reactive oxygen species in organic oxidation, demonstrating efficiency over five consecutive trials. Additionally, G-CeO2 NPs exhibit potent antibacterial activity against both gram-positive and gram-negative bacteria. This study presents an innovative, and efficient approach to environmental remediation, shedding light on the potential of G-CeO2 NPs in addressing environmental pollution challenges.

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White metatitanic acid H2TiO3 (HTO)/TiO2 composites with co‐exposed [111]‐, {010} and {101} facets were successfully synthesized by employing the white suspension of [TMA+]2[TiO3]2− as the precursor via a hydrothermal soft chemical synthesis method in the presence or absence of 1‐ethyl‐3‐methylimidazolium bromide ([Emim]Br), 4‐bromine imidazole (Bmim) and 1‐methyl‐3‐propylimidazole tetrafluoroborate ([Pmim]BF4) ionic liquids. The structure, morphology, specific surface areas, microstructure, surface properties, and charge migration behaviors of HTO/TiO2 composites vary depending on the selected ionic liquid. The apparent rate constant of the Bmim‐HTO/TiO2 composite was the highest, at 0.0353 min−1, which was approximately 1.35, 1.38, 1.44, 2.67, and 88.25 times higher than that of [Pmim]BF4‐HTO/TiO2 (0.0262 min−1), [Emim]Br‐HTO/TiO2 (0.0256 min−1), No IL‐HTO/TiO2 (0.0245 min−1), CM‐TiO2 (0.0132 min−1) and Blank samples (0.0004 min−1), respectively. Compared with CM‐TiO2 and other HTO/TiO2 samples, the Bmim‐HTO/TiO2 composite featuring cuboid anatase TiO2 nanocrystals with co‐exposed [111]‐facets and {101} facets, exhibited superior photocatalytic activity in degrading methylene blue (MB) under ultraviolet light irradiation. This exceptional performance can be attributed to its cooperative effects, including a larger specific surface area, the co‐exposure of [111]‐ and {101} facets, a suitable heterojunction structure, and the most efficient charge carrier separation. This work introduces a hydrothermal soft chemical process for preparing HTO/TiO2 composite with controllable morphology and co‐exposed reactive facets, which holds promise for practical applications in removing organic pollutants from printing and dyeing wastewater.

No abstract available

Bismuth telluride (Bi2Te3) is an available thermoelectric material with the lowest band gap among bismuth chalcogenides, revealing a broad application in photocatalysis. Unfortunately, its size and morphology related to a radio-catalysis property have rarely been explored. Herein, an ethylenediaminetetraacetic acid (EDTA)-assisted hydrothermal strategy was introduced to synthesize polytypic Bi2Te3 nanoplates (BT NPs) that exhibit size-dependent radio-sensitization and metabolism characteristics in vivo. By simply varying the molar ratio of EDTA/Bi3+ during the reaction, BT NPs with different sizes and morphologies were obtained. EDTA acting as chelating agent and "capping" agent contributed to the homogeneous growth of BT NPs by eliminating dangling bonds and reducing the surface energy of different facets. Further analyzing the size-dependent radio-sensitization mechanism, larger-sized BT NPs generated holes that preferentially catalyzed the conversion of OH- to ·OH when irradiated with X-rays, while the smaller-sized BT NPs exhibited faster decay kinetics producing higher 1O2 levels to enhance radiotherapy effects. A metabolomic analysis revealed that larger-sized BT NPs were oxidized into Bi(Ox) in the liver via a citrate cycle pathway, whereas smaller-sized BT NPs accumulated in the kidney and were excreted in urine in the form of ions by regulating the metabolism of glutamate. In a cervical cancer model, BT NPs combined with X-ray irradiation significantly antagonized tumor suppression through the promotion of apoptosis in tumor cells. Consequently, in addition to providing a prospect of BT NPs as an efficient radio-sensitizer to boost the tumor radiosensitivity, we put forth a strategy that can be universally applied in synthesizing metal chalcogenides for catalysis-promoted radiotherapy.

Development of synthetic strategies selectively yielding single crystals is desired owing to the facet-dependent chemical reactivities. Recent advances in electrochemical materials synthesis yielded nanomaterials that are surfactant-free, however, typically in polycrystalline forms. In this work, an electrochemical synthetic strategy selectively yielding single-crystalline nanoparticles by implementation of surface-selective heating of the working electrode is developed. Single crystals of copper, silver, gold, and platinum are afforded, and the crystallinity verified by electron diffraction and chemical reactivity studies. Notably, Cu (100) surface prepared by electrochemical synthesis yielded high single product selectivity when applied to electrochemical CO2 reduction catalysis.

Owing to a wide range of industrial applications and fundamental importance, delafossite compounds have gathered tremendous interest in research community. In this study, the formation of hexagonal nanoplates of AgInO 2 mainly dominated by (00l) facets with no metallic Ag impurity, reported using a facile hydrothermal route at 180 o C using KOH as mineralizer by adopting a factorial design approach. Rietveld analysis of the powder XRD pattern and SAED confirms the rhombohedral system of AgInO 2 . FE-SEM image shows a uniform hexagonal plate-like morphology with an average width of about 300 nm and thickness of 70 nm. XPS and EDX analysis confirm K + ion free AgInO 2 . A specific surface area of about 48.5 m 2 /g is arrived from N 2 adsorption studies. Temperature-dependent AC impedance measurements revealed an activation energy of 0.24 eV/f.u. Further, TG-DTA studies found that the compound is stable in air up to 595 °C.

Piezoelectric catalysis, utilizing mechanical energy to generate reactive oxygen species (ROS), has emerged as a promising strategy in environmental remediation. However, developing high-performance piezocatalysts operable under low-frequency conditions remains a huge demand and challenge. Herein, an innovative supramolecular-driven hydrothermal strategy is proposed for precise morphology regulation and synthesis of ZnO/CuO piezocatalysts. Using self-assembled natural betulinic acid as a dynamic soft template, four types of ZnO/CuO heterojunctions are successfully synthesized with progressively tuned morphologies, including rod-like (RPs), airship-like (APs), star-like (SPs), and urchin-like (UPs) particles, which exhibit enhanced sharp protrusions and highly bendable features. Structural modulation and ROS mechanistic analyses reveal a distinct piezoelectric trend of UPs > SPs > APs > RPs. This implies that higher strain probability or larger strain gradients, resulting from increased sharp protrusions, lead to improved piezoelectric performance. Significantly, the UPs exhibit exceptional piezocatalytic activity under low-frequency mechanical stirring, achieving a degradation rate constant of 40.8 × 10-3 min-1 for dye rhodamine and an 88.4% bacterial inhibition rate at merely 60 ng mL-1. This work not only provides a promising option for the application of commercial high-performance piezocatalysts in environmental regeneration but also highlights the potential of supramolecular-mediated morphology regulation strategies for designing advanced piezocatalysts adapted to diverse applications.

The precise control of the crystal phase during the synthesis of nickel selenide (NixSey) nanocrystals is crucial, as crystal structure and composition significantly influence their reactivity, growth kinetics, and properties. The cation exchange (CE) method provides a versatile and robust approach for synthesizing nanomaterials, enabling precise control over phase, composition, and morphology. However, the application of this method for phase-controlled synthesis of NixSey nanocrystals has received limited research attention. Here, we present a morphology-guided CE method for the synthesis of spinel Ni3Se4 nanoparticles (NPs) and rhombic Ni3Se2 nanorods (NRs), wherein berzelianite Cu2-xSe NPs and NRs are employed as sacrificial templates for CE with Ni2+. This phase-controlled behavior, which is guided by morphology and dependent on the stacking length of the close-packed facets, relies on the rearrangement of the Se2- sublattice accompanied by CE, providing a unique and precise approach to controlling phase during nanocrystal synthesis. Additionally, the obtained Ni3Se4 NPs and Ni3Se2 NRs exhibit structure-dependent catalytic activities in the oxygen evolution reaction.

Nanoporous metals have unique potentials for energy applications with a high surface area despite the percolating structure. Yet, a highly corrosive environment is required for the synthesis of porous metals with conventional dealloying methods, limiting the large-scale fabrication of porous structures for reactive metals. In this study, we synthesize a highly reactive Mg nanoporous system through a facile organic solution-based approach without any harsh etching. The synthesized nanoporous Mg also demonstrates enhanced hydrogen sorption kinetics and reveals unique kinetic features compared to Mg nanoparticles. The well-crystallized Mg nanoporous structure exhibits crystalline facet-dependent hydrogen sorption characteristics, featuring gradually improved hydrogen storage capacity up to 6 wt.% upon cycling. Also, continuum kinetics models coupled to atomistic simulations reveal that the compressive stress developed during the hydrogenation of nanoporous Mg enhances the sorption kinetics, as opposed to the sluggish kinetics under tensile stress in core-shell nanoparticles. It is expected that the synthetic strategy conceived in this study can be further implemented to prepare different kinds of reactive porous metals in a facile and scalable way for the development of large-scale and distributed hydrogen storage systems for the emerging low-carbon hydrogen economy. A highly reactive Mg nanoporous system is prepared via a facile organic solution-based method for advanced solid-state hydrogen storage. It reveals that Mg crystalline facets and stress states lead to improved hydrogen storage kinetics

We report the use of poly(amidoamine) dendrimers as stabilizers to synthesize ultrathin Au nanowires (NWs) with a diameter of 1.3 nm via a hydrothermal approach. The formation of uniform Au NWs was optimized by varying the Au/Ag salt molar ratio, dendrimer stabilizers and reaction solvent, temperature and time. A novel growth mechanism involving a synergic facet-dependent deposition/reduction of Ag(I) and oriented migration of Au atoms is proposed based on density functional theory calculations and the experimental results. This work can significantly expand the scope of dendrimers as stabilizers to generate metal NWs in aqueous solution that may be further functionalized for different applications.

Titanium dioxide (TiO2) is one of the most extensively studied oxides as an active catalyst or catalyst support, particularly in energy and environmental applications, but the atomistic mechanisms governing its dynamic response to reactive environments and their correlation to reactivity remain largely elusive. Using in situ environmental transmission electron microscopy (ETEM), synchrotron X-ray diffraction (XRD), ambient-pressure X-ray photoelectron spectroscopy (AP-XPS), temperature-programmed reduction (TPR), reactivity measurements, and theoretical modeling, we reveal the dynamic interplay between oxygen loss and replenishment of anatase TiO2 under varying reactive conditions. Under H2 exposure, anatase TiO2 undergoes surface reduction via lattice oxygen loss, forming Ti3O5. In contrast, CO2 exposure induces oxygen replenishment, reversing stoichiometry. In mixed H2/CO2 environments, the reverse water-gas shift (RWGS) reaction proceeds selectively on stepped and high-indexed TiO2 surfaces, whereas the thermodynamically stable TiO2(101) surface remains inactive and intact. Critically, H2 pretreatment generates oxygen vacancies on TiO2(101), transforming it into an active Ti3O5 or defect-rich surface that catalyzes RWGS. By correlating surface structure, defect dynamics, and gas-phase interactions, this work deciphers the competition between H2-driven reduction and CO2-driven oxidation pathways at the atomic scale. These insights establish defect engineering as a strategic lever to activate inert TiO2 facets, advancing the design of adaptive catalysts for sustainable fuel synthesis technologies.

Octahedral anatase particles (OAPs) were prepared by an ultrasonication (US)-hydrothermal (HT) reaction of partially proton-exchanged potassium titanate nanowires (TNWs). The structural/physical properties of OAP-containing samples, including specific surface area, crystallinity, crystallite size, particle aspect ratio, composition and total OAP content, were analyzed. Photocatalytic activities of samples were measured under irradiation (>290 nm) for oxidative decomposition of acetic acid (CO2 system) and dehydrogenation of methanol (H2 system) under aerobic and deaerated conditions, respectively. Total density of electron traps (ETs) was measured by double-beam photoacoustic spectroscopy (DB-PAS). Mobility and lifetime of charge carriers (electrons) were investigated by the time-resolved microwave conductivity (TRMC) method. The effects of synthesis parameters, i.e., HT duration, HT temperature and US duration, on properties and photocatalytic activities of final products were examined in detail. The sample prepared with 1 h US duration and 6 h HT duration at 433 K using 267 mg of TNWs in 80 mL of Milli-Q water exhibited the highest photocatalytic activity. It was found that change in HT duration or HT temperature while keeping the other conditions the same resulted in changes in all properties and photocatalytic activity. On the other hand, duration of US treatment, before HT reaction, influenced the morphology of both the reagent (by TNWs breaking) and final products (change in total OAP content); samples prepared with various US durations exhibited almost the same structural/physical properties evaluated in this study but were different in morphology and photocatalytic activity. This enabled clarification of the correlation between morphology and photocatalytic activity, i.e., the higher the total OAP content was, the higher was the level of photocatalytic activity, especially in the CO2 system. Although the decay after maximum TRMC signal intensity (Imax) was almost constant for all samples used in this study, photocatalytic activities were roughly proportional to Imax, which tended to be proportional to total OAP content. Assuming that Imax corresponds to the product of density of electrons in mobile shallow ETs and their mobility, the results suggest that OAP particles have beneficial shallow ETs in higher density and thereby the OAP content governs the photocatalytic activities. Thus, morphology-dependent photocatalytic activity of OAP-containing particles was reasonably interpreted by density of ETs presumably located on the exposed {101} facets.

No abstract available

Crystal facet engineering has been proved as a versatile approach in modulating the photocatalytic activity of semiconductors. However, the facet-dependent properties and underlying mechanisms of spinel ZnFe2O4 in photocatalysis still have rarely been explored. Herein, ZnFe2O4 nanoparticles with different {001} and {111} facets exposed were successfully synthesized via a facile hydrothermal method. Facet-dependent photocatalytic degradation performance towards gaseous toluene under visible light irradiation was observed, where truncated octahedral ZnFe2O4 (ZFO(T)) nanoparticles with both {001} and {111} facets exposed exhibited a suppressing performance than the others. The formed surface facet junction between {010} and {100} facets was responsible for the improved activity by separating photogenerated e-/h+ pairs efficiently to reduce their recombination rate. Photogenerated electrons and holes were demonstrated to be immigrated onto {001} and {111} facets, separately. Intriguingly, EPR trapping results indicated that both •O2- and •OH were abundantly present in the ZFO(T) sample under the visible light irradiation as major reactive oxygen species involved in the photocatalytic degradation process. Additionally, further investigation revealed that {001} facets played a predominant role in activating photogenerated transient species H2O2 into •OH, beneficially boosting the intrinsic photocatalytic activity. This work has not only presented a promising strategy in regulating photocatalytic performance though the synergetic effect of facet junction and specific facet activation but also broadened the application of facet engineering with multiple effects simultaneously cooperated.

Certain nanomaterials can filter and alter unwanted compounds due to a high surface area, surface reactivity, and microporous structure. Herein, γ-Bi2MoO6 particles are synthesized via a colloidal hydrothermal approach using organically modified Laponite as a template. This organically modified Laponite interlayer serves as a template promoting the growth of the bismuth molybdate crystals in the [010] direction to result in hybrid Laponite-Bi2MoO6 particles terminating predominantly in the {100} crystal facets. This resulted in an increase in particle size from lateral dimensions of <100 nm to micron scale and superior adsorption capacity compared to bismuth molybdate nanoparticles. These {100}-facet terminated particles can load both cationic and anionic dyes on their surfaces near-spontaneously and retain the photocatalytic properties of Bi2MoO6. Furthermore, dye-laden hybrid particles quickly sediment, rendering the task of particle recovery trivial. The adsorption of dyes is completed within minutes, and near-complete photocatalytic degradation of the adsorbed dye in visible light allowed recycling of these particles for multiple cycles of water decontamination. Their adsorption capacity, facile synthesis, good recycling performance, and increased product yield compared to pure bismuth molybdate make them promising materials for environmental remediation. Furthermore, this synthetic approach could be exploited for facet engineering in other Aurivillius-type perovskites and potentially other materials.

Combining montmorillonite (MMT), a layered silicate clay, with carbon quantum dots (CQD) is a promising strategy to develop hybrid nanomaterials with enhanced and tunable properties. In this work, we explore the structure–property relationships in montmorillonite–carbon quantum dot (MCQD) hybrid nanomaterials synthesized through two distinct routes. In Route 1, pre-synthesized CQDs using citric acid and urea as precursors were physically mixed with MMT, giving rise to MCQD-R1 hybrid nanomaterials. In Route 2, MMT was added in situ in the CQD reaction medium before thermal treatment, with contact times from 1 to 16 h, generating MCQD-R2-1 and MCQD-R2-16, respectively. Structural and spectroscopy techniques were employed to investigate the resulting hybrids. PXRD analysis revealed that the synthesis conditions preserved the crystalline structures of both CQD and MMT clay. The FT-IR indicated that in the MCQD-R1, the interactions with CQD occur primarily via the interlayer water molecules in MMT, whereas in the MCQD-R2-16 samples, the establishment of new chemical bonds involving the carbonyl group of CQD takes place. UV-Vis spectroscopy shows improved colloidal stability of MCQD-R2 hybrids compared to pristine CQDs. Finally, hemolysis assays demonstrated hemolytic activity below 5%, indicating good biocompatibility of the synthesized hybrid nanomaterials.

Rheology, small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) analysis, zeta potential measurement, scanning electron microscopy (SEM), and micro-FTIR and absorbance spectroscopy were used to enlighten the controversial literature about LAPONITE® materials. Our data suggest that pristine LAPONITE® in water does not form hydrogels induced by the so-called "house of cards" assembly, but rather forms Wigner glasses governed by repulsive forces. Ionic interactions between anisotropic LAPONITE® nanodiscs, sodium polyacrylate and inorganic salts afforded hydrogels that were transparent, self-standing, moldable, strong, and biocompatible with shear-thinning and self-healing behavior. An extensive study on the role of salts in the gelification process dictates a trend that relates the valence of cations with the viscoelastic properties of the bulk material (G' values follow the trend, monovalent < divalent < trivalent). These hydrogels present G' values up to 5.1 × 104 Pa, which are considered high values for non-covalent hydrogels. Hydrogels crosslinked with sodium phosphate salts are biocompatible, and might be valid candidates for injectable drug delivery systems due to their shear-thinning behavior with rapid self-healing after injection.

Zeta potential indirectly reflects a charge of the surface of nanoparticles in solutions and could be used to represent the stability of the colloidal solution. As processes of synthesis, testing and evaluation of new nanomaterials are expensive and time-consuming, so it would be helpful to estimate an approximate range of properties for untested nanomaterials using computational modeling. We collected the largest dataset of zeta potential measurements of bare metal oxide nanoparticles in water (87 data points). The dataset was used to develop quantitative structure–property relationship (QSPR) models. Essential features of nanoparticles were represented using a modified simplified molecular input line entry system (SMILES). SMILES strings reflected the size-dependent behavior of zeta potentials, as the considered quasi-SMILES modification included information about both chemical composition and the size of the nanoparticles. Three mathematical models were generated using the Monte Carlo method, and their statistical quality was evaluated (R2 for the training set varied from 0.71 to 0.87; for the validation set, from 0.67 to 0.82; root mean square errors for both training and validation sets ranged from 11.3 to 17.2 mV). The developed models were analyzed and linked to aggregation effects in aqueous solutions.

To control the photocatalytic activity, it is essential to consider several parameters affecting the structure of ordered multicomponent TiO2-based photocatalytic nanotubes. The lack of systematic knowledge about the relationship between structure, property, and preparation parameters may be provided by applying a machine learning (ML) methodology and predictive models based on the quantitative structure-property-condition relationship (QSPCR). In the present study, for the first time, the quantitative mapping of preparation parameters, morphology, and photocatalytic activity of 136 TiO2 NTs doped with metal and non-metal nanoparticles synthesized with the one-step anodization method has been investigated via linear and nonlinear ML methods. Moreover, the developed QSPCR model, for the first time, provides systematic knowledge supporting the design of effective TiO2-based nanotubes by proper structure manipulation. The proposed computer-aided methodology reduces cost and speeds up the process (optimize) of efficient photocatalysts’ design at the earliest possible stage (before synthesis) in line with the sustainability-by-design strategy.

Group IV semiconductor nanomaterials, including silicon nanocrystals and more recently nanosheets, are emerging as promising candidates for next-generation optoelectronic applications due to their tunable room-temperature photoluminescence and compatibility with CMOS technologies. However, the intrinsic indirect bandgaps of Group IV seminconductors remains a key limitation. Here, we highlight our group's contributions toward understanding structure-property relationships in solution-processable Group IV semiconductor nanocrystals and nanosheets - specifically, understanding how their structure, surface chemistry, and chemical composition influence affect properties such as bandgap.

In this study, we propose Explainable Multimodal Machine Learning (EMML), which integrates the analysis of diverse data types (multimodal data) using factor analysis for feature extraction with Explainable AI (XAI), for carbon nanotube (CNT) fibers prepared from aqueous dispersions. This method is a powerful approach to elucidate the mechanisms governing material properties, where multi-stage fabrication conditions and multiscale structures have complex influences. Thus, in our case, this approach helps us understand how different processing steps and structures at various scales impact the final properties of CNT fibers. The analysis targeted structures ranging from the nanoscale to the macroscale, including aggregation size distributions of CNT dispersions and the effective length of CNTs. Furthermore, because some types of data were difficult to interpret using standard methods, challenging-to-interpret distribution data were analyzed using Negative Matrix Factorization (NMF) for extracting key features that determine the outcome. Contribution analysis with SHapley Additive exPlanations (SHAP) demonstrated that small, uniformly distributed aggregates are crucial for improving fracture strength, while CNTs with long effective lengths are significant factors for enhancing electrical conductivity. The analysis also identified thresholds and trends for these key factors to assist in defining the conditions needed to optimize CNT fiber properties. EMML is not limited to CNT fibers but can be applied to the design of other materials derived from nanomaterials, making it a useful tool for developing a wide range of advanced materials. This approach provides a foundation for advancing data-driven materials research.

Zinc oxide (ZnO) based nanomaterials have been used in various gas sensors due to the wide band gap (3.37eV), large exciton binding energy and high mobility of charge carriers of ZnO. In this work, nanocrystalline ZnO nanofiber mats were synthesized through combined sol-gel electrospinning techniques followed by calcination, in which poly(styrene-co-acrylonitrile) and zinc acetate were used as the binder and precursor, respectively. Average diameter of the ZnO nanofibers decreased from 400 to 60nm, while their grain size and crystallinity were enhanced by increasing the calcination temperature. Morphology and structure of the ZnO nanofiber mats were characterized by high resolution transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. ZnO nanofiber mats were found to be superhydrophilic (contact angle was close to 0°) by contact angle measurements. The sensitivity of these ZnO nanofibers in detecting gaseous ammonia was tested using an indigenous set up. Due to their high surface area and superhydrophility, these ZnO nanofiber mats were highly sensitive in sensing gaseous ammonia and the sensitivity of these mats increased as a function of their calcination temperatures.

Nanomaterials allow designing targeted therapies, facilitate molecular diagnostics, and are therefore enabling platforms for personalized medicine. A systematic science and a predictive understanding of molecular/supramolecular structure relationships and nanoparticle structure/biological property relationships are needed for rational design and clinical progress but are hampered by the anecdotal nature, nonsystematic and nonrepresentative nanomaterial assortment, and oligo-disciplinary approach of many publications. Here, we find that a systematic and comprehensive multidisciplinary approach to production and exploration of molecular-structure/nanostructure relationship and nano-bio structure/function relationship of medical nanomaterials can be achieved by combining systematic chemical synthesis, thorough physicochemical analysis, computer modeling, and biological experiments, as shown in a nanomaterial family of amphiphilic, micelle-forming oxazoline/siloxane block copolymers suited for the clinical application. This comprehensive interdisciplinary approach leads to improved understanding of nanomaterial structures, allows good insights into binding modes for the nanomaterial protein corona, induces the design of minimal cell-binding materials, and yields rational strategies to avoid toxicity. Thus, this work contributes to a systematic and scientific basis for rational design of medical nanomaterials.

We present a combined strategy of experiments and theoretical modeling for understanding the evolution of the morphology and plasmonic properties of gold nanostars (GNSs) in the seed-mediated synthesis by changing the poly(vinylpyrrolidone) (PVP) molecular weight, PVP concentration, and synthesis temperature. A dramatic change of the morphology of GNSs as a function of these synthesis parameters is observed that is related to variations of the plasmonic properties and thus surface-enhanced Raman spectroscopy (SERS) enhancement. We observe the favorable growth of anisotropic GNS structures with sharp protruding tips using PVP of low molecular weight and of rounded GNSs with short protruding tips using PVP of high molecular weight. The PVP concentration has less influence on the core size than on the tip length of GNSs. The high synthesis temperature causes the rounding of the GNS structure. Finite-difference time-domain (FDTD) simulations reveal a remarkable correlation of the GNS morphology with the plasmonic properties as well as the SERS enhancement. The maximum local electric field enhancement occurs at the apex of the sharp protruding tips of the GNSs. The weak plasmonic coupling is observed between the protruding tips of GNSs because of their large separation distance, and increasing the number of protruding tips beyond two only increases the extinction cross section without further red-shifting the plasmon peak. A resonance overlap of the plasmon band with the incident laser wavelength is responsible for the morphology-dependent plasmonic properties and SERS enhancement. The present work demonstrates that a mechanistic understanding of the structural evolution of GNSs along with their morphology-plasmonic property correlation can be achieved through the combination of experimental investigations and FDTD-based theoretical modeling.

The macroscopic properties of materials are governed by their microscopic structure which depends on the materials' composition (i.e., building blocks) and processing conditions. In many classes of synthetic, bioinspired, or natural soft and/or nanomaterials, one can find structural anisotropy in the microscopic structure due to anisotropic building blocks and/or anisotropic domains formed through the processing conditions. Experimental characterization and complementary physics-based or data-driven modeling of materials' structural anisotropy are critical for understanding structure-property relationships and enabling targeted design of materials with desired macroscopic properties. In this pursuit, to interpret experimentally obtained characterization results (e.g., scattering profiles) of soft materials with structural anisotropy using data-driven computational approaches, there is a need for creating real space three-dimensional structures of the designer soft materials with realistic physical features (e.g., dispersity in building block sizes) and anisotropy (i.e., aspect ratios of the building blocks, their orientational and positional order). These real space structures can then be used to compute and complement experimentally obtained characterization results or be used as initial configurations for physics-based simulations/calculations that can then provide training data for machine learning models. To address this need, we present a new computational approach called CASGAP - Computational Approach for Structure Generation of Anisotropic Particles - for generating any desired three dimensional real-space structure of anisotropic building blocks (modeled as particles) adhering to target distributions of particle shape, size, and positional and orientational order.

The assembly of 3-dimensional covalent organic frameworks on the surface of carbon nanotubes is designed and successfully developed for the first time via the hybridization of imine-based covalent organic frameworks (COF-300) and oxidized MWCNTs by one-pot chemical synthesis. The resulting hybrid material ox-MWCNTs@COF exhibits a conformal structure that consists of a uniform amorphous COF layer covering the ox-MWCNT surface. The measurements of individual hybrid nanotube mechanical strength performed with atomic force microscopy provide insights into their stability and resistance. The results evidence a very robust hybrid tubular nanostructure that preserves the benefits obtained from COF, such as CO2 adsorption. Further digestion of the organic structure with aniline enables the study of the interplay between the hybrid interface and its nanomechanics. This new hybrid nanomaterial presents exceptional mechanical and electrical properties, merging the properties of the CNT template and COF-300.

An emerging class of two-dimensional semiconductor materials, metal-organic chalcogenolates (MOCs), have garnered significant attention due to the strong excitonic effects arising from their intrinsic soft, hybrid multiquantum-well structures. However, modifying excitonic transitions that strongly couple to the argentophilic networks and constructing their structure-property relationships in MOCs remain daunting challenges. Here, we use silver phenylselenolate (AgSePh) as a model system to manipulate excitonic behavior and uncover the fundamental photophysical mechanisms through pressure engineering. A bright broadband Stokes-shifted emission is observed in AgSePh crystals along with the disappearance of blue narrow emission upon compression, which is attributed to the pressure-induced carrier transformation from free exciton to self-trapping exciton states. The considerable compressibility of the Ag-Se inorganic monolayer, driven by weakly bound argentophilic interactions, generates pronounced argentophilic intralayer distortion while simultaneously enhancing exciton-phonon coupling and excitonic oscillator strength. This work demonstrates the remarkable tunability of excitonic properties in layered MOCs. Pressure brightens the self-trapped exciton emission in 2D semiconducting metalorganic chalcogenolates by manipulating exciton-phonon coupling and argentophilicity-driven lattice distortion.

No abstract available

This work demonstrates how particle size and facet orientation in copper nanocrystals influence CO2 electroreduction efficiency in a static H‐cell system. Three Cu nanocrystal morphologies are studied: blood flow (BF, {100} facets, larger size), spherical (SP, {111} facets, similar size as BF), and trigonal (TR, {100} facets, different size). Although BF and TR share the {100} orientation, they show contrasting selectivity BF favors ethylene (≈60% Faradaic efficiency at −90 mA cm−2), while TR promotes formate (85% FE at −39 mA cm−2), underscoring the effect of size. SP, with the same size as BF but {111} facets, produces CO (78% FE at −35 mA cm−2), highlighting the role of facet orientation. Operando Raman spectroscopy identifies key intermediates associated with C1 versus C2 pathways, while density functional theory simulations (DFT) provide mechanistic insights into energy barriers, emphasizing how size and facet orientation govern electrochemical CO2 reduction reaction (CO2RR) performance. These findings offer a new approach to overcoming static system limitations by optimizing Cu nanocrystal properties, paving the way for rational catalyst design without the need for additives or complex modifications.

We regulate the particle size and surface facet of single-crystal (SC) Li(Ni,Mn)2O4 cathode materials to give guidance without compromising electrochemical performance. Adjusting the molten salt method with selecting sintering aids , we synthesized size controlled SC particles, both small and large, and evaluated their electrochemical characteristics focusing on differences in the lithiation/delithiation reactivity depending on size with crystal facet conditions. While the initial charge capacity is similar to each other, the given cathode using an small SC particle with ordered crystalline and uniform particle sizes (≤5 um) exhibits outstanding rate capability with stable capacity retention irrespective of loading density and current density, which indicates the stable lithium transport during the repetitive electrochemical reactions. The dependency of the impedance response with change in the electrode resistances as well as the stability during the cycle reactions in conjunction with the post-mortem the Li distribution by using laser-induced breakdown spectroscopy as function of porosity change and cell degradation are thoroughly discussed from the standpoint of regulated particle property.

This study investigates the effect of surface modifications of the titanium substrate on the growth of electrochemically deposited copper. These materials are intended to serve as cathodes in the electroreduction of nitrates in aqueous solutions. Surface modifications included the use of hydrogen fluoride for titanium etching and anodization to promote the growth of a structured titania nanotube array. The effect of an intermediate calcination step for the nanotubes before deposition was assessed along with a comparison to an untreated substrate electrode. The materials were comprehensively characterized by SEM, XRD, contact angle, potentiodynamic tests, EIS, and cyclic voltammetry. Their electrocatalytic ability was tested in the reduction of aqueous solutions containing nitrates. The results reveal that surface finishing impacted the shape and size of the Cu microparticles, as well as the nucleation mechanism enabling a crystal-facet-controllable synthesis. All the materials exhibited microsized copper particles with a spherical shape with some clusters. On the etched titanium surface, a high number of heterogeneous submicroscopic particles were also present. The thermally treated anodized substrate promoted the development of a combination of sparse microparticles corresponding to defect sites in amorphous titanium and the presence of a diffuse coating of octahedral nanosized particles whose growth was promoted by the tetragonal structure of anatase crystals. Electrochemical tests display reduced charge transfer resistance upon copper deposition on the modified substrates, which is indicative of the enhanced conductivity of the coated materials. Additionally, cyclic voltammetry and electrolysis experiments reveal the electrodes' potential for nitrate reduction, showing a better response for the etched titanium substrate (30% nitrate removal, after 2 h at 25 mA cm-2).

Morphology and geometrical dimensions play crucial roles in the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) for water splitting. Decahedral BiVO4 was synthesized through a facile hydrothermal process, which exhibited superior charge injection efficiency to the nanoporous counterpart prepared by the traditional method. More importantly, the crystal size and facet proportion of BiVO4 decahedrons were facilely controlled. The charge separation efficiency can be significantly improved with a reduction in the crystal size and an increase in (040) facet exposure. A new method was developed for rate law analysis: illumination intensity-modulated oxygen evolution reaction rate versus open circuit potential difference, which suggested that the surface reaction kinetics was not affected by facet regulation. Furthermore, after decorating the FeOOH and NiOOH as dual oxygen evolution cocatalysts, an enhanced photocurrent density of 3.2 mA cm-2 at 1.23 V versus reversible hydrogen electrode and interfacial charge injection efficiency of 97.0% can be reached. Our work inspires the development of facet-regulated BiVO4 photoanodes with high charge injection efficiency in the PEC field and provides a feasible route to enhance its charge separation efficiency.

No abstract available

No abstract available

The sensitivity and quantitative accuracy of surface-enhanced Raman scattering (SERS) are the main factors that restrict its application. Here, novel Au nanoscale convex polyhedrons (Au NCPs) were designed and fabricated to solve these problems via an embedded standard, including eight pods and six small protrusions. Spherical Au seeds regrew into different sizes of Au NCPs with a face-centered cubic structure. This morphology is due to the dual mechanism of the 4-aminothiophene (4-ATP) molecule that serves as an internal standard and a surface ligand regulator combined with the regulatory role of hexadecyl trimethyl ammonium chloride. The results show that Au NCPs were enclosed by high-index {12 9 1} facets, which greatly improved the local plasma resonance and reduced the lowest SERS detectable concentration of pyrene in standard seawater to 0.5 nM. An effective reference was produced by embedding 4-ATP with a relative standard deviation value less than 2.97% (in the same batch) and 3.92% (between different batches). Our research offers a new strategy for morphological regulation of metal nanocrystals, which is useful for the preparation of highly sensitive SERS substrates and trace analysis.

Fe3O4 and Fe2O3 nanocrystals have been successfully synthesized from iron sand by the coprecipitation method using a semi-automatic coprecipitator. The composition of iron sand used was 12, 18, and 24 gram, to investigate the performance of the coprecipitator. The synthesized Fe3O4 and Fe2O3 nanocrystals were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), and Vibrating Sample Magnetometer (VSM). The best phase composition of Fe3O4 nanocrystals is 100 wt% which has a magnetite crystal size range of 5 to 13 nm, and the mass obtained is in the range of 7.01 to 12.71 gram. The best phase composition of Fe2O3 nanocrystals is 99.89 wt% hematite (α – Fe2O3) which has a crystal size range of 23 to 26 nm, the mass obtained is in the range of 3.51 to 7.49 gram. The highest gain of Fe3O4 and Fe2O3 nanocrystals was 67.62% and 41.58%, respectively, obtained from 18 gram iron sand composition. The morphology of Fe3O4 and Fe2O3 nanocrystals is almost spherical. The highest magnetization was obtained from Fe3O4 nanocrystals with a saturation magnetization of 8.87 emu/gram. The magnetic properties of Fe3O4 and Fe2O3 nanocrystals are ferrimagnetic and weak ferrimagnetic, respectively.

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Nanosizing drug crystals has emerged as a successful approach to enabling oral bioavailability, as increasing drug crystal surface area improves dissolution kinetics and effective solubility. Recently, bottom-up methods have been developed to directly assemble nanosized crystals by leveraging polymer and surfactant excipients during crystallization to control crystal size, morphology, and structure. However, while significant research has investigated how polymers and other single additives inhibit or promote crystallization in pharmaceutical systems, there is little work studying the mechanistic interactions of multiple excipients on drug crystal structure and the extent of crystallinity, which can influence formulation performance. This study explores how the structure and crystallinity of a model hydrophobic drug crystal, fenofibrate, change as a result of competitive interfacial chemisorption between common nonionic surfactants (polysorbate 80 and sorbitan monooleate) and a surface-active polymer excipient (methylcellulose). Classical molecular dynamics simulations highlight how key intermolecular interactions, including surfactant-polymer complexation and surfactant screening of the crystal surface, modify the resulting crystal structure. In parallel, experiments generating drug nanocrystals in hydrogel thin films validate that drug crystallinity increases with an increasing weight fraction of surfactant. Simulation results reveal a connection between accelerated dynamics in the bulk crystal and the experimentally measured extent of crystallinity. To our knowledge, these are the first simulations that directly characterize structural changes in a drug crystal as a result of excipient surface composition and relate the experimental extent of crystallinity to structural changes in the molecular crystal. Our approach provides a mechanistic understanding of crystallinity in nanocrystallization, which can expand the range of orally deliverable small molecule therapies.

Colloidal quantum dots (QDs), notably lead sulfide (PbS) QDs, represent a promising platform for short-wave infrared (SWIR) photodetection, offering a cost-effective and scalable alternative to conventional indium gallium arsenide (InGaAs) systems. This study investigates the pivotal role of PbS QD size in optimizing the hole transport layer (HTL) for SWIR photodetectors, addressing the interplay among film morphology, electronic structure, and device performance. Through the precise synthesis of monodisperse PbS QDs (3.33-4.14 nm) and solid-state ligand exchange with 1,2-ethanedithiol (EDT), we reveal that smaller QDs, while benefiting from strong quantum confinement and superior electron blocking, suffer from pronounced volumetric shrinkage and microcracking due to high ligand-to-QD ratios. Conversely, larger QDs enhance film integrity but introduce surface-facet-dependent defects and increase dark current density. Combining transmission electron microscopy, absorption spectroscopy, photoluminescence quenching, and space-charge-limited current analysis, we elucidate the size-dependent trade-offs governing HTL functionality. Devices with intermediate-sized QDs (e.g., 4.04 nm) achieve peak external quantum efficiency (55.74%), responsivity (0.54 A/W), and specific detectivity (5.50 × 1012 Jones), while smaller QDs (3.33 nm) excel in trap state suppression and faster response speed (1.0 μs rise and 1.3 μs fall). These findings establish a materials-by-design framework for tailoring QD size to balance mechanical stability and optoelectronic performance, advancing solution-processed SWIR imaging technologies.

In the quest for efficient photocatalysts, cancrystal shape engineering outperform size reduction in enhancing photocatalytic performance? This is investigated using CsPbBr3 perovskite nanocrystals (PNC) by comparing conventional amine‐capped, 6‐facet cubic morphology with newly developed 26‐facet polyhedral nanocrystals synthesized via an amine‐free approach. Surprisingly, the larger polyhedral PNCs are far better at converting CO2 into CO, despite their lower surface‐to‐volume ratio than the 6‐facet cubic PNCs. They achieve a total CO yield of 394 µmol g−1 with a conversion rate of 35.81 µmol g−1 h−1 without any help from extra co‐catalysts. To the best of the author's knowledge, this represents the highest reported CO evolution rate using 3‐dimensional PNCs as the sole photocatalyst, with performance comparable to or exceeding systems employing co‐catalysts. This enhanced activity arises from longer excited‐state lifetimes, improved charge transport, larger electrochemical surface area (ECSA), and a higher density of charge carriers, as confirmed by optical and electrochemical studies. Computational studies show that some specific facets of this polyhedra bind CO2 molecules more strongly and provide the optimized binding energy to efficiently release the final product(CO). With excellent 12‐h stability, these shape‐controlled nanocrystals enable a pathway toward sustainable energy technology applications worldwide.

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The size- and shape-dependent properties of inorganic nanocrystals have given rise to many fascinating physical phenomena and enabled new applications that cannot be achieved in bulk materials. Therefore, it is important to explore the roles of different crystal facets, how they interact with species on the surfaces, and how they transform under stimuli. A number of applications, including catalysis and plasmonics, depend on exactly which facets are accessible, and how these facets are able to interact with the surrounding environment. This presentation will explore the role of facets in surface functionalization and the in situ transformations of crystal morphologies and phases. The work presented will demonstrate how atomic-resolution transmission electron microscopy can provide precise information about surfaces, interfaces, and atomic transformations. It will highlight the important role of surface structures, crystal packing, and the underlying nanocrystal morphology.

Lead halide perovskite quantum dots (QDs) have become a promising class of nanomaterials due to their simple, scalable synthesis and high luminescence efficiency. However, their high ionicity and low lattice formation energy make controlling the synthesis of perovskite QDs particularly challenging. Although there have been significant advances in controlling the size of perovskite QDs, increasing efforts have focused on selecting and stabilizing their various surface facets. In this review, we examine recent developments in morphology-controlled isotropic perovskite QDs, emphasizing the latest techniques for managing surface facet exposure, facet passivation, and the optical and chemical properties of these QDs. We also explore future challenges and opportunities for precise synthesis control, especially regarding shape control of strongly confined QDs, which is vital for understanding the relationship between structure and propertiesultimately improving the performance and stability of perovskite QD-based optoelectronic devices and photocatalysts.

The agglomeration of silver nanoparticles (AgNPs) results in poor antibacterial performance, and the accumulation of silver in the human body threatens human health. Preparing a matrix is a technique worth considering as it not only prevents the aggregation of AgNPs but also reduces deposition of AgNPs in the human body. In this paper, carboxy-cellulose nanocrystals (CCNC) were prepared by a simple one-step acid hydrolysis method. Chito-oligosaccharides (CSos) were grafted onto the surface of CCNC to form CSos-CCNC composite nanoparticles. CCNC and CSos-CCNC were used as stabilizers for deposing AgNPs and two types of complexes—AgNPs-CCNC and AgNPs-CSos-CCNC—were obtained, respectively. The influence of the two stabilizer matrices—CCNC and CSos-CCNC—on the morphology, thermal behavior, crystal structure, antibacterial activity, and cell compatibility of AgNPs-CCNC and AgNPs-CSos-CCNC were examined. The results showed that the AgNPs deposited on the CSos-CCNC surface had a smaller average diameter and a narrower particle size distribution compared with the ones deposited on CCNC. The thermal stability of AgNPs-CSos-CCNC was better than that of AgNPs-CCNC. AgNPs did not affect the crystalline structure of CCNC and CSos-CCNC. The antibacterial activity of AgNPs-CSos-CCNC was better than that of AgNPs-CCNC based on antibacterial studies using Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae. The cytotoxicity of AgNPs-CSos-CCNC was remarkably lower than that of AgNPs-CCNC.

The performance of nanocrystal (NC) catalysts could be maximized by introducing rationally designed heterointerfaces formed by the facet- and spatio-specific modification with other materials of desired size and thickness. However, such heterointerfaces are limited in scope and synthetically challenging. Herein, we applied a wet chemistry method to tunably deposit Pd and Ni on the available surfaces of porous 2D-Pt nanodendrites (NDs). Using 2D silica nanoreactors to house the 2D-PtND, an 0.5-nm-thick epitaxial Pd or Ni layer (e-Pd or e-Ni) was exclusively formed on the flat {110} surface of 2D-Pt, while a non-epitaxial Pd or Ni layer (n-Pd or n-Ni) was typically deposited at the {111/100} edge in absence of nanoreactor. Notably, these differently located Pd/Pt and Ni/Pt heterointerfaces experienced distinct electronic effect to influence unevenly in electrocatalytic synergy for hydrogen evolution reaction (HER). For instance, an enhanced H2 generation on the Pt{110} facet with 2D-2D interfaced e-Pd deposition and faster water dissociation on the edge-located n-Ni overpowered their facet-located counterparts in respective HER catalysis. Therefore, a feasible assembling of the valuable heterointerfaces in the optimal 2D n-Ni/e-Pd/Pt catalyst overcame the sluggish alkaline HER kinetics, with a catalytic activity 7.9 times higher than that of commercial Pt/C.

We present a one‐pot colloidal synthesis method for producing monodisperse multi‐metal (Co, Mn, and Fe) spinel nanocrystals (NCs), including nanocubes, nano‐octahedra, and concave nanocubes. This study explores the mechanism of morphology control, showcasing the pivotal roles of metal precursors and capping ligands in determining the exposed crystal planes on the NC surface. The cubic spinel NCs, terminated with exclusive {100}‐facets, demonstrate superior electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline media compared to their octahedral and concave cubic counterparts. Specifically, at 0.85 V, (CoMn)Fe2O4 spinel oxide nanocubes achieve a high mass activity of 23.9 A/g and exhibit excellent stability, highlighting the promising ORR performance associated with {100}‐facets of multi‐metal spinel oxides over other low‐index and high‐index facets. Motivated by exploring the correlation between ORR performance and surface atom arrangement (active sites), surface element composition, as well as other factors, this study introduces a prospective approach for shape‐controlled synthesis of advanced spinel oxide NCs. It underscores the significance of catalyst shape control and suggests potential applications as nonprecious metal ORR electrocatalysts.

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Pt based materials are the most efficient catalysts for hydrogen evolution reaction (HER). However, the high cost and low earth abundance severely retard its commercial applications. Moreover, degradation of noble metal materials inevitably occurs during long-term HER process, especially in acidic media. Herein, core-shell structured high-index facet PtNi nanocrystals (HIF-PtNi NCs) coated with a polydopamine derived carbon nanofilm (cPDA) were fabricated for HER with enhanced catalytic activity and significantly improved stability to minimize Pt loadings. HIF-PtNi NCs possess a uniform concave morphology with average diameter of ∼42 nm in which the predominantly exposed crystal lattices spacing is 0.196 nm that is attributed to the (200) planes. The exposed high-energy surfaces exhibit better HER performance than low-energy surfaces such as commercial Pt/C catalyst and can reduce Pt loadings for commercial applications. Experiments and density functional theory (DFT) calculations confirmed that the amorphous carbon nanofilm significantly inhibited the deformation and degradation of the HIF-PtNi NCs catalyst in the core. HIF-PtNi NCs coated with cPDA nanofilm (HIF-PtNi NCs/cPDA) exhibits the HER overpotentials of 42 mV and the Tafel slope of 36.3 mV dec-1 at current density of 10 mA cm-2 with a low Pt loading of 140 μg cm-1. HIF-PtNi NCs/cPDA shows almost no decay in HER activity after an accelerated durability test that conducted at a current density of 150 mA cm-2 for 100 h in 0.5 M H2SO4 solution.

Metal–organic frameworks (MOFs) of MOF-199 with three distinct morphologies—cubic (hexahedral)-A, octahedral-B and tetradecahedral-C—were prepared by solvothermal method via adjusting the amount of coordination modulator of lauric acid. Meanwhile, absorbing hybrids of MOF-199@multi-walled carbon nanotubes (MWCNTs) with a three-dimensional structure were constructed via π–π stacking interactions between benzene ring π-electrons in the organic ligand of MOF-199 and π electronic of MWCNTs. Scanning electron microscopy images demonstrated that MOFs particles with three distinct morphologies were obtained, with an average particle size of approximately 2 μm. The aim of this study is to investigate the influence of MOF morphology on the absorption performance. Due to the increased number of facets and relatively abundant heterogeneous interfaces of tetradecahedral MOF-199-C, the RLmin of MOF-199-C@MWCNTs hybrids reach up to −48.16 dB, which is higher than that of cubic MOF-199-A@MWCNTs (−23.21 dB) hybrids and octahedral MOF-199-B@MWCNTs (−45.77 dB) hybrids. The results indicated that increasing the number of facets promotes multiple scattering and internal reflection of electromagnetic waves, which increases the heterogeneous interfaces and promotes absorption performance.

18-facet polyhedron Cu7S4 nanocrystal and CuS sphere were prepared from Cu2O precursor, and CuS flower was synthesized through a simple solvothermal approach. Their electrochemical performances were investigated towards H2O2 and it was interesting to discover that Cu7S4 nanocrystal had the best electrochemical catalysis compared with CuS sphere and CuS flower. It can deduce that the special structure of Cu7S4 nanocrystal endowed it more exposed active points, higher surface area and higher Cu/S ratio. Therefore, Cu7S4 nanocrystal was firstly employed to prepare a nonenzymatic biosensor for H2O2. Satisfactory results were obtained. In addition, a label-free sensing platform for prostate specific antigen (PSA) was constructed based on electrochemical catalysis towards H2O2 of Cu7S4 nanocrystal. The label-free immunosenosr offered accurate PSA in the range of 0.001-15 ng/mL with the detection limit of 0.001 ng/mL. Besides, the immunosensor possessed good sensitivity, selectivity and stability and could detect PSA in real sample. More importantly, this work demonstrated that Cu7S4 nanocrystal hold great promising application in electrochemical sensors.

Great consideration is placed on the choice of capping agents’ base on the proposed application, in order to cater to the particular surface, size, geometry, and functional group. Change in any of the above can influence the characteristics properties of the nanomaterials. The adoption of hexadecylamine (HDA) as a capping agent in single source precursor approach offers better quantum dots (QDs) sensitizer materials with good quantum efficiency photoluminescence and desirable particles size. Structural, morphological, and electrochemical instruments were used to evaluate the characterization and efficiency of the sensitizers. The cyclic voltammetry (CV) results display both reduction and oxidation peaks for both materials. XRD for SnS/HDA and SnS photosensitizers displays eleven peaks within the values of 27.02° to 66.05° for SnS/HDA and 26.03° to 66.04° for SnS in correlation to the orthorhombic structure. Current density–voltage (I–V) results for SnS/HDA exhibited a better performance compared to SnS sensitizers. Bode plot results indicate electrons lifetime (τ) for SnS/HDA photosensitizer have superiority to the SnS photosensitizer. The results connote that SnS/HDA exhibited a better performance compared to SnS sensitizers due to the presence of HDA capping agent.

Semiconductor oxides are frequently used as active photocatalysts for the degradation of organic agents in water polluted by domestic industry. In this study, sol-gel ZnO thin films with a grain size in the range of 7.5–15.7 nm were prepared by applying a novel two-step drying procedure involving hot air treatment at 90–95 °C followed by conventional furnace drying at 140 °C. For comparison, layers were made by standard furnace drying. The effect of hot air treatment on the film surface morphology, transparency, and photocatalytic behavior during the degradation of Malachite Green azo dye in water under ultraviolet or visible light illumination is explored. The films treated with hot air demonstrate significantly better photocatalytic activity under ultraviolet irradiation than the furnace-dried films, which is comparable with the activity of unmodified ZnO nanocrystal powders. The achieved percentage of degradation is 78–82% under ultraviolet illumination and 85–90% under visible light illumination. Multiple usages of the hot air-treated films (up to six photocatalytic cycles) are demonstrated, indicating improved photo-corrosion resistance. The observed high photocatalytic activity and good photo-corrosion stability are related to the hot air treatment, which causes a reduction of oxygen vacancies and other defects and the formation of interstitial oxygen and/or zinc vacancies in the films.

The high-temperature stability and good photoelectrochemical performance make CsPbBr3 a promising material for application as a photoanode, such as in water splitting and glucose detection. However, studies on the heat treatment of CsPbBr3 in solution and its application as a glucose oxidizer in photoanodes are still limited. This research aims to analyze the influence of heating treatment on CsPbBr3 solution and glucose concentration on the glucose oxidation performance of perovskite photoanodes in a photoelectrochemical system. First, CsPbBr3 solution was prepared using the Ligand Assisted Reprecipitation (LARP) method and heated at temperature of 110°C. Subsequently, FTO/TiO2/CsPbBr3 photoanodes were fabricated and examined using X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM) to determine the formed phases and morphology. The results of these tests showed that the particle size increased with heating, with a transformation from grains to rods or wires, as well as platelets and cubes due to agglomeration resulting from ligand loss during heating. The FTO/TiO2/CsPbBr3 photoanodes were then subjected to CV test, with exposure to light in a 0.5 M KOH electrolyte solution and varying glucose concentrations of 0.1 M, 0.2 M, and 0.3 M, to determine the oxidation and reduction reactions. The Cyclic Voltammetry (CV) test results showed that the FTO/TiO2/CsPbBr3 photoanodes generally exhibited high photocurrent densities in the electrolyte under illumination conditions. This was further supported by Fourier Tranform Infrared Spectroscopy (FTIR) test results, which indicated several changes in the identified chemical bonds of the electrolyte and glucose mixture post reaction on the CV test. Therefore, The FTO/TiO2/CsPbBr3 photoanode is a suitable option for glucose fuel cell.

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Plasmonic nanorings are promising building blocks for a variety of applications, including optical and biological sensing, and energy because the open inner spaces of the nanorings exhibit a high surface‐to‐area ratio and possess unique optical properties that are different from solid nanostructures. However, the simple architecture of mono‐rim based structures leads to low electromagnetic near‐field confinement, which requires a more complex structure to facilitate effective interaction with light. Herein, we report on recent progress of synthetic strategies for fabricating plasmonic nanorings using both top‐down and bottom‐up approaches. First, we introduce the conventional methods for achieving classical ring architectures. Then, we discuss rationally designed synthesis methods for creating advanced and structurally unique nanostructures to increase near‐field enhancement. This process involves multi‐step chemical toolkits that enable control over the shape and the introduction of repeated units in a single entity. Then, we explore the potential applications of complex nanoring architectures.

We report on morphology-controlled remote epitaxy via hydrothermal growth of ZnO micro- and nanostructure crystals on graphene-coated GaN substrate. The morphology control is achieved to grow diverse morphologies of ZnO from nanowire to microdisk by changing additives of wet chemical solution at a fixed nutrient concentration. Although the growth of ZnO is carried out on poly-domain graphene-coated GaN substrate, the direction of hexagonal sidewall facet of ZnO is homogeneous over the whole ZnO-grown area on graphene/GaN because of strong remote epitaxial relation between ZnO and GaN across graphene. Atomic-resolution transmission electron microscopy corroborates the remote epitaxial relation. The non-covalent interface is applied to mechanically lift off the overlayer of ZnO crystals via a thermal release tape. The mechanism of facet-selective morphology control of ZnO is discussed in terms of electrostatic interaction between nutrient solution and facet surface passivated with functional groups derived from the chemical additives.

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The synthesis of BiPO4 : Eu3+ phosphors has been achieved via a wet chemical process. X-ray diffraction patterns show that the phase of as-prepared samples matches very well with the standard BiPO4 structure. At 395 nm, the highest excitation intensity was observed. Following 395 nm excitation, two characteristic emission peaks at 592 nm and 616 nm were shown. At 0.5 mole percent of Eu3+ ions, concentration quenching occurred. The particle size is within the micrometer range, according to the SEM magnification. The chromaticity coordinates for wavelengths 592 nm and 616 nm are (X=0.586, Y=0.412) and (X=0.682, Y=0.317), respectively. The findings imply that prepared phosphor may be used to create white LEDs.

2D nanomaterials have attracted broad interest in the field of biomedicine owing to their large surface area, high drug‐loading capacity, and excellent photothermal conversion. However, few studies report their “enzyme‐like” catalytic performance because it is difficult to prepare enzymatic nanosheets with small size and ultrathin thickness by current synthetic protocols. Herein, a novel one‐step wet‐chemical method is first proposed for protein‐directed synthesis of 2D MnO2 nanosheets (M‐NSs), in which the size and thickness can be easily adjusted by the protein dosage. Then, a unique sono‐chemical approach is introduced for surface functionalization of the M‐NSs with high dispersity/stability as well as metal‐cation‐chelating capacity, which can not only chelate 64Cu radionuclides for positron emission tomography (PET) imaging, but also capture the potentially released Mn2+ for enhanced biosafety. Interestingly, the resulting M‐NS exhibits excellent enzyme‐like activity to catalyze the oxidation of glucose, which represents an alternative paradigm of acute glucose oxidase for starving cancer cells and sensitizing them to thermal ablation. Featured with outstanding phototheranostic performance, the well‐designed M‐NS can achieve effective photoacoustic‐imaging‐guided synergistic starvation‐enhanced photothermal therapy. This study is expected to establish a new enzymatic phototheranostic paradigm based on small‐sized and ultrathin M‐NSs, which will broaden the application of 2D nanomaterials.

Metastable‐phase intermetallic compounds (IMCs) provide great flexibility to modify the electronic structure and surface coordination environment of metallic catalysts for various reactions. However, the synthesis of metastable‐phase IMCs with high catalytic performance remains a great challenge due to their thermodynamically unstable nature. Here, a wet‐chemical epitaxial growth strategy to synthesize metastable‐phase Pd‐Bi intermetallic nanocrystals (NCs) is reported. β‐Pd3Bi and γ‐Pd5Bi3 intermetallic NCs are epitaxially grown on the templates of face‐centered cubic Pd3Pb nanocubes and hexagonal close‐packed PtBi nanoplates, achieving Pd3Pb@Pd3Bi and PtBi@Pd5Bi3 core–shell NCs, respectively. The obtained Pd3Pb@Pd3Bi NCs possess a mass activity and specific activity of 8.52 A mg−1Pd and 11.59 mA cm−2 for ethanol oxidation reaction, which is 7.5 and 3.6 times as high as those of commercial Pd/C, respectively. Meanwhile, Pd3Pb@Pd3Bi NCs possess superior stability than commercial Pd/C. This work advances the design and synthesis of high‐performance metastable‐phase IMCs, opening an avenue for electrocatalytic ethanol oxidation and beyond.

The synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods is introduced. Various architectures based on different kinds of seeds or templates are illustrated, and their growth mechanisms are discussed in detail. The applications of epitaxial heterostructures in optoelectronics, thermoelectrics, and catalysis are discussed. The synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods is introduced. Various architectures based on different kinds of seeds or templates are illustrated, and their growth mechanisms are discussed in detail. The applications of epitaxial heterostructures in optoelectronics, thermoelectrics, and catalysis are discussed. Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics, thermoelectrics, and catalysis. Until now, various kinds of epitaxial heterostructures have been constructed. In this minireview, we will first introduce the synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods. Various architectures based on different kinds of seeds or templates are illustrated, and their growth mechanisms are discussed in detail. Then, the applications of epitaxial heterostructures in optoelectronics, catalysis, and thermoelectrics are described. Finally, we provide some challenges and personal perspectives for the future research directions of semiconductor nanomaterial-based epitaxial heterostructures.

Wet chemical synthesis of hydroxyapatite (HAp) nanostructures was carried out with different solution pH values (9, 10 and 11) and sintering temperatures (300°C, 500°C, 700°C and 900°C). The effects of pH and sintering temperature on the structural and morphological properties of nanocrystalline HAp powders were presented. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were performed to obtain the crystalline structure, chemical composition, morphology and particle size of the HAp powders. The TEM analysis is used in order to observe the rod- and flake-like HAp structures. XRD confirms the presence of both HAp hexagonal and monetite phases, although the monetite phase was less abundant in the resultant powders. Increase in pH reduced the monetite phase and enhanced Ca/P ratio from 1.7 to 1.83. Additionally, an increment in sintering temperature increased the crystallite size from 20 to 56 nm. The SEM analysis revealed the formation of semi-spherical and flake-like HAp structures with preferential flake morphology. An increase in pH and sintering temperature resulted in the growth and coalescence of crystals resulting in a porous capsular morphology. The FTIR analysis confirmed the reduction of carbonate stretching modes with an increase in pH and H–O–H antisymmetric stretching mode is eliminated for powders sintered at 900°C confirming the formation of stable and porous HAp powders.

The research on Zinc oxide nanoparticles has become very important on these days due to its unique property and wide range of applications in all the branches of science. In this study, we synthesized ZnO nanoparticles through a simple and cost-effective wet chemical precipitation approach. The XRD spectra revealed the hexagonal wurtzite structure in the prepared ZnO nanoparticles. The UV-Vis absorption peak of the as - prepared ZnO sample was identified at 301.2 nm and was observed to be blue shifted in comparison to the bulk counterpart. The transmittance analysis of the prepared ZnO sample showed very high transmittance to the visible range of light. The widening of the optical band gap was observed in the preparation ZnO sample. The band gap of the synthesized ZnO sample was found to be 3.7943 eV. The theoretical estimation of particle size in the prepared ZnO sample was performed using the Brus model and the particle size was estimated to be 4.38 nm. This study revealed the potential application of prepared ZnO nanoparticles as transparent electrode in solar cell.

Abstract In the present study, Barium Titanate (BaTiO3) nanoparticles were synthesized using one of the best route chemical method that is sol-gel auto combustion method. The structural and dielectric properties were investigated by powder X-ray diffraction (XRD), LCR meter and the results are reported herein. The phase purity and structural determination was carried by XRD technique at room temperature. The analysis of XRD patterns revealed of formation of single phase tetragonal structure. The lattice parameters ‘a’ and ‘c’ were obtained using XRD data and obtained lattice parameters matches with reported value. Average crystallite size was determined using Debye–Scherrer’s formula and is found to be 6.4 Å indicating nanocrystalline nature. Dielectric properties like dielectric constant and dielectric loss tangent was investigated using LCR-Q meter method at varying frequencies. Both dielectric constant and dielectric loss tangent decreases with increasing frequencies. The PE characteristics and other studies are in progress.

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The nanocomposites of Franklinite (Fe2O4Zn) doped Zincte (ZnO) were synthesized through wet chemical (co-precipitation) technique followed by heat treatment. Metal chlorides and metal oxides are used as precursors for the formation of composites. The asprepared sample composites were subjected to sintering for two hours at the temperature of 300 °C. The detail spectral study and the effect of concentration of precursor salt on the structural parameters were done by using XRD and Rietveld refinement method. The occurrence of two crystalline phases (Fe2O4Zn and ZnO) was estimated from XRD data through Rietveld refinement. It was observed that the Fe2O4Zn have a cubic structure with space group Fd-3m (227), whereas ZnO has hexagonal structure with space group P 63 mc (186). The Wyckoff positions and rietveld refinement parameters like goodness factor, Bragg R factor, Rp value, Rexp were calculated. Effect of varying concentration of precursor on development of complete ferrite phase of structure was discussed.

Concave morphologies provide noble metal nanocrystals (NCs) with unique performances due to large specific surface areas, high curves, hot spots, and elevated energy facets. As a result, concave morphologies have attracted considerable attention in many areas. However, most NCs with concave shapes are currently made of a single metal, leaving plenty of room for easy wet chemical synthesis and structural analysis of unique concave structures, especially bimetallic compounds. In this work, concave octahedral Pt-Pd alloy NCs with high-index {hhl} faces were synthesized using glycine as a coordination molecule and polyvinylpyrrolidone as the surfactant and reducing agent. The high-index facets coupled with the synergistic and electronic effects between Pt and Pd provided concave octahedral Pt-Pd alloy NCs with excellent activity and stability toward the electrooxidation of formic acid when compared to their convex counterparts and commercial Pt black.

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Silicon‐based biomaterials play an indispensable role in biomedical engineering; however, due to the lack of intrinsic functionalities of silicon, the applications of silicon‐based nanomaterials are largely limited to only serving as carriers for drug delivery systems. Meanwhile, the intrinsically poor biodegradation nature for silicon‐based biomaterials as typical inorganic materials also impedes their further in vivo biomedical use and clinical translation. Herein, by the rational design and wet chemical exfoliation synthesis of the 2D silicene nanosheets, traditional 0D nanoparticulate nanosystems are transformed into 2D material systems, silicene nanosheets (SNSs), which feature an intriguing physiochemical nature for photo‐triggered therapeutics and diagnostic imaging and greatly favorable biological effects of biocompatibility and biodegradation. In combination with DFT‐based molecular dynamics (MD) calculations, the underlying mechanism of silicene interactions with bio‐milieu and its degradation behavior are probed under specific simulated physiological conditions. This work introduces a new form of silicon‐based biomaterials with 2D structure featuring biodegradability, biocompatibility, and multifunctionality for theranostic nanomedicine, which is expected to promise high clinical potentials.

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Zinc oxide nanoparticles were prepared from Zn5(CO3)2(OH)6 precursor, capped with poly(vinylpyrrolidone) (PVP), and annealed at 600 °C. The obtained powders were characterized by a powder X-ray diffraction (PXD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–visible spectroscopy (UV–vis), Raman spectroscopy, infrared spectroscopy (IR), thermal analysis (TGA/DTA), and third-order nonlinear (NL) optical measurement. Morphological evaluation by TEM and SEM measurements indicated that the precursor micro-particles are ball-shaped structures composed of plates with a thickness of approximately 10 nm. ZnO thin films, as well as ZnO/polymer multilayer layouts, were obtained by wet chemical methods (spin- and dip-coating). Surface topography and morphology of the obtained films were studied by SEM and AFM microscopy. Films with uniformly distributed ZnO plates, due to the erosion of primary micro-particles were formed. The fabricated specimens were also analyzed using a spectroscopic ellipsometry in order to calculate dielectric function and film thickness.

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