异质结催化剂在液体中催化性能的稳定性研究

In this work, a novel synthetic strategy to construct a structurally advanced bifunctional electrocatalyst via Ar/NH3 radio‐frequency plasma‐assisted nitridation and subsequent high‐temperature selenization is proposed. The resulting self‐supporting electrode, denoted as p‐NiSe2/Ni@Ni3N/NCNT@CC, consists of selenium‐vacancy‐rich NiSe2/Ni@Ni3N nanoparticles (NPs) uniformly anchored on nitrogen‐doped carbon nanotubes (NCNTs) in situ grown on carbon‐cloth (CC). The formation of this ternary heterostructure is governed by interactions between plasma‐generated reactive species (NH*, NH2*, Ar*) and Ni NPs. It demonstrates outstanding bifunctional performance and stability in 0.1 m KOH, featuring a half‐wave potential for oxygen‐reduction reaction (ORR) of 0.80 V, an overpotential of 311 mV for oxygen‐evolution reaction (OER) at 30 mA cm⁻2, and a minimal ΔE of 0.74 V, surpassing commercial Pt/C+RuO2. Liquid zinc–air batteries (L‐ZABs) using this catalyst as the air cathode deliver a high peak power‐density of 137.94 mW cm⁻2 and stable cycling over 1 000 cycles, with minimal voltage polarization. More impressively, it serves as a competitive self‐supporting electrode in flexible all‐solid‐state ZABs (ASS‐ZABs), achieving 1.49 V open‐circuit voltage (OCV), 106.8 mW cm⁻2 peak power‐density, and excellent cycling and low‐temperature performance. DFT calculations confirm that the enhanced activity and durability stem from the synergistic effects of heterostructure engineering, selenium vacancy modulation, and conductive carbon integration.

Interface engineering strategy has been developed to design efficient catalysts for boosting electrocatalytic performance in past few decades. Herein, heterojunctions of PrCoO3/Co3O4 nanocages (PCO/Co3O4 NCs) with atomic-level engineered interfaces and rich oxygen vacancies are proposed for Zn-air batteries. The synthesized product shows exceptional bifunctional activity and robust stability towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The enhanced catalytic capacity is primary attributed to the synergistic effect of PCO/Co3O4, evidenced by the experimental results and theoretical calculations. More importantly, the PCO/Co3O4 NCs assembled liquid Zn-air battery exhibits a power density of 182 mW cm-2 and a long-term operation of 185 h. When assembled into solid-state cable type battery, this newly designed catalyst also reaches a stable open circuit voltage (1.359 V) and a peak power density of 85 mW cm-3. Our findings provide essential guidelines of engineering heterostructured electrocatalysts for future wearable electronic devices.

This study successfully synthesized Ag2WO4/CuBi2O4 (ACBO) composite materials via a two-step method. Tetracycline (TET) was employed as a model pollutant to evaluate the sonocatalytic performance of Ag2WO4/CuBi2O4 composite materials. Among all samples, ACBO-30 exhibited the most outstanding sonocatalytic activity. Under optimal experimental conditions, the removal efficiency of TET reached 98.06 ± 1.10%. Based on the results of active species trapping experiments and X-ray photoelectron spectroscopy, it was confirmed that an S-scheme heterojunction formed between Ag2WO4 and CuBi2O4, which effectively promoted the separation of electron-hole pairs and significantly enhanced the sonocatalytic performance of CuBi2O4. Cyclic experiments further demonstrated that the Ag2WO4/CuBi2O4 composite catalyst possessed excellent reusability and stability. Through high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, several plausible conversion pathways of the TET were proposed. Biological toxicity tests verified that the sonocatalytic technology could degrade TET into less toxic byproducts. This study provides valuable insights into the design and development of novel sonocatalysts for the efficient treatment of pharmaceutical wastewater.

Metal organic framework (MOF) is currently-one of the key catalysts for oxygen evolution reaction (OER), but its catalytic performance is severely limited by electronic configuration. In this study, cobalt oxide (CoO) on nickel foam (NF) was first prepared, which then wrapped it with FeBTC synthesized by ligating isophthalic acid (BTC) with iron ions by electrodeposition to obtain CoO@FeBTC/NF p-n heterojunction structure. The catalyst requires only 255 mV overpotential to reach a current density of 100 mA cm-2, and can maintain 100 h long time stability at 500 mA cm-2 high current density. The catalytic properties are mainly related to the strong induced modulation of electrons in FeBTC by holes in the p-type CoO, which results in stronger bonding and faster electron transfer between FeBTC and hydroxide. At the same time, the uncoordinated BTC at the solid-liquid interface ionizes acidic radicals which form hydrogen bonds with the hydroxyl radicals in solution, capturing them onto the catalyst surface for the catalytic reaction. In addition, CoO@FeBTC/NF also has strong application prospects in alkaline electrolyzers, which only needs 1.78 V to reach a current density of 1 A cm-2, and it can maintain long-term stability for 12 h at this current. This study provides a new convenient and efficient approach for the control design of the electronic structure of MOF, leading to a more efficient electrocatalytic process.

In this study, we applied a two-step electrochemical anodization process to produce highly porous nanostructured nickel suboxides. We then annealed these materials in different environments: air, Ar, and Ar/H2. Annealing in a reductive environment (Ar/H2) resulted in a Ni-NiO heterojunction with a high defect density, as confirmed by the Mott–Schottky analysis. Our results demonstrate that these defects and active sites significantly enhance the electrocatalytic activity for the oxygen evolution reaction (OER). Utilizing X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical analysis, we demonstrate that the heterojunction system containing Ni-NiO, formed through annealing in an Ar/H2 atmosphere, acts as a highly efficient electrocatalyst for the OER. This catalyst achieves an impressively low overpotential of 293 mV at 10 mA cm–2, a Tafel slope of 74 mV dec–1, and exhibits outstanding stability, maintaining performance over 1000 cycles. Notably, our most optimized NiO x electrode outperforms the conventional reference RuO2 electrode by a factor of 1.72. Our findings demonstrate the potential of binder-free Ni-NiO heterojunctions in developing high-performance electrocatalysts for alkaline electrolysis.

The development of cost-effective bifunctional electrocatalysts remains a great challenge. In this work, high-performance Fe2P-CoMoP/NF catalysts were prepared using the strategy of constructing phosphide heterostructures with localized photothermal effect. At 10 mA·cm-2, the HER overpotential of Fe2P-CoMoP/NF is 30.8 mV and the OER overpotential is 180.9 mV. Compared to Fe2P/NF and CoMoP/NF, the higher content of oxygen vacancies in the phosphorylated heterostructure Fe2P-CoMoP/NF has the potential to enhance intrinsic activity and improve the photothermal effect. With the assistance of localized photothermal effect, the HER (η100 = 72.7 mV) and OER (η100 = 252.3 mV) overpotentials of Fe2P-CoMoP/NF decreased by 35.8 % and 9.9 %, which were more significant than those of CoMoP/NF and Fe2P/NF. Meanwhile, the Fe2P-CoMoP/NF catalyst has excellent stability, maintaining 96 % at -500 mA·cm-2 and 94 % at 300 mA·cm-2 after 100 h. In addition, overall water splitting can be carried out using solar panels with a voltage of 1.42 V, which shows its potential for application in combination with sustainable energy sources.

The electrocatalytic conversion of oxygen to hydrogen peroxide offers a promising pathway for sustainable energy production. However, the development of catalysts that are highly active, stable, and cost-effective for hydrogen peroxide synthesis remains a significant challenge. In this study, a novel polyacid-based metal-organic coordination compound (Cu-PW) was synthesized using a hydrothermal approach. Cu-PW served as a precursor to construct a composite electrocatalyst featuring a heterointerface between CuWO4 and WO3 (CuWO4/WO3) through pyrolysis. The CuWO4/WO3 heterojunction exhibits an impressive H2O2 selectivity of 91.84% at 0.5 V, marking a 19.65% improvement compared to the pristine Cu-PW. Furthermore, the CuWO4/WO3 catalyst demonstrates exceptional stability, maintaining continuous operation for 29 h. At 0.1 V, it delivers a hydrogen peroxide yield of 1537.8 mmol g-1 h-1, with a Faraday efficiency (FE) of 85%. Additionally, this catalyst effectively degrades methyl blue, achieving a 95% removal from an aqueous system within 30 min. Theoretical analysis further corroborates the high electroactivity of CuWO4/WO3 heterojunction structure. The Cu-O-W bridge formed during the reaction facilitates interfacial electron transport and enhances the role of the W-O bond in proton adsorption and transfer kinetics. This strong interfacial coupling in CuWO4/WO3 promotes electron transfer and the formation of *OOH intermediates, thereby favoring hydrogen peroxide generation. Hence, the as-prepared CuWO4/WO3 demonstrates great potential as an efficient electrocatalyst for the green synthesis of hydrogen peroxide, exhibiting high efficiency as a two-electron oxygen reduction reaction catalyst. This work offers a new approach for fabricating CuWO4/WO3 electrocatalyst with high electroactivity and selectivity, paving the way for cost-effective and sustainable hydrogen peroxide production, significantly reducing reliance on the conventional anthraquinone process.

Herein, we have assembled an anionic donor-acceptor (D-A) conjugated polyelectrolyte dots (Pdots), based on bithiophene units-containing backbone and sulfonate modified side chain (PCP-2F-Li), with porous g-C3N4 nanosheets (CNNS) into a new 0D/2D heterojunction (PCP-2F-Li Pdots/CNNS). The well-matched energy levels of PCP-2F-Li and CNNS and the strong electron-donating sulfinates in PCP-2F-Li can significantly accelerate the interfacial electron transfer in heterojunction, while the strong hydrophilicity of PCP-2F-Li can improve the interface wetting and promote the photocatalytic water-splitting. As such, PCP-2F-Li Pdots/CNNS can be used for efficient co-catalyst-free water splitting with a hydrogen evolution rate (HER) of 1932.1 μmol·h-1·g-1 over 6 runs, which is 1.85 and 2.29 times of hydrophobic F8T2 Pdots/CNNS and Pt-assisted CNNS, respectively. The apparent quantum yield (AQY) of PCP-2F-Li Pdots/CNNS can reach 7.87 %, 7.73 % and 5.60 % at 420, 450 and 475 nm, respectively. The findings highlight a new type of the Pdots-assisted heterojunctions for high-efficiency and durable co-catalyst-free water splitting.

The environmental contamination caused by organophosphorus pesticides (for example, triazophos) is an escalating concern. To mitigate this issue, this study introduces a novel Al6Si2O13/WO2.72 (ASO/WO) nanocomposite photocatalyst, which markedly enhances the photocatalytic degradation of triazophos. The optimized nanocomposite material with a 60.0 % ASO loading (60-ASO/WO) achieves a degradation rate of 86.3 % for triazophos within 140.0 min, marginally exceeding 60-ASO/WO3 (72.6 %) and significantly outperforming individual ASO (65.0 %), WO (59.5 %), and WO3 (56.2 %). This catalyst retains 88.9 % of its activity after five cycles, showcasing exceptional efficiency and stability. Additionally, its electrochemical surface area (ECSA, 310.0 cm2), total organic carbon (TOC, removal rate of 73.7 %), photocurrent, and electrochemical impedance are all optimal. X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and theoretical calculations elucidate the critical role of oxygen vacancies and the S-scheme heterojunction in augmenting charge separation and photocatalytic performance, corroborating the synergistic effect of oxygen defects and the S-scheme. While individual factors can enhance photocatalytic activity, their combination results in a more pronounced effect. Liquid chromatography-mass spectrometry (LCMS) identifies the principal degradation intermediates, including 1-phenyl-3-hydroxy-1, 2, 4-triazole, diethyl thiophosphate, and 3, 5, 6-trichloro-2-pyridinol, underscoring the material's potential in environmental remediation.

Replacing the kinetically slow oxygen evolution reaction (OER) with urea electro-oxidation significantly reduces the energy requirement for electrolysis of water. However, designing and optimizing efficient electrocatalysts for the industrial application of urea oxidation coupled to hydrogen production remains a challenge. Herein, we construct a C/A-NixP/NiOH heterojunction catalyst with actually abundant amorphous/crystalline interfaces for the urea oxidation reaction (UOR) by an interfacial-sequential treatment method of electrodeposition and low-temperature gas-phase phosphatization on carbon cloth (CC). Remarkably, in UOR, the C/A-NixP/NiOH catalyst required only 1.332 V to reach a current density of 10 mA cm-2 with negligible potential decay over 12 h. The excellent performance is attributed to the synergistic interaction between the inner amorphous NiOH layer and the outer crystalline NixP layer, as well as the abundant amorphous/crystalline interface, an interfacial structure that can expose more active sites as well as enhance the intrinsic activity, thus improving the reaction kinetics and stability of UOR. This work paves the way for the development of low-cost and high-efficiency catalysts for urea oxidation.

Heterostructure catalysts are considered as promising candidates for promoting the oxygen evolution reaction (OER) process due to their strong electron coupling. However, the inevitable dissolution and detachment of the heterostructure catalysts are caused by the severe reconstruction, dramatically limiting their industrial application. Herein, the NiFe-layered double hydroxide (LDH) nanosheets attached on Mo-NiO microrods (Mo-NiO@NiFe LDH) by the preoxidation strategy of the core NiMoN layer are synthesized for ensuring the high catalytic performance and stability. Owing to the enhanced electron coupling and preoxidation process, the obtained Mo-NiO@NiFe LDH exhibits a superlow overpotential of 253 mV to achieve a practically relevant current density of 1000 mA cm-2 for OER with exceptional stability over 1200 h. Notably, the overall water splitting system based on Mo-NiO@NiFe LDH reveals remarkable stability, maintaining the catalytic activity at a current density of 1000 mA cm-2 for 140 h under industrial harsh conditions. Furthermore, the Mo-NiO@NiFe LDH demonstrates outstanding activity and long-term durability in a practical alkaline electrolyzer assembly with a porous membrane, even surpassing the performance of IrO2. This work provides a new sight for designing and synthesizing highly stable heterojunction electrocatalysts, further promoting and realizing the industrial electrocatalytic OER.

The rational construction of efficient and stable noble-metal-free oxygen evolution reaction (OER) electrocatalysts that work under a industrial-level current density in alkaline environments are urgently needed and challenging. Here we propose a Ti3C2Tx MXene-based synthetic method for constructing Co2P/Ti3C2Tx, Fe2P/Ti3C2Tx and Co2P/Fe2P multiple heterojunctions (labeled as CoFe-P@MXene) by using strong electrostatic adsorption-electrodeposition-low temperature phosphorization. The obtained CoFe-P@MXene possesses abundant three-dimensional porous structures and inherits the high conductivity of MXene. Experiment results and density functional theory calculations indicate that the formation of multi-heterojunctions between transition metal phosphides and Ti3C2Tx MXene can modulate the electronic structure of active sites Co and Fe, alter the d-band center, and thereby optimize the adsorption energy of oxygen-containing intermediates on the active sites. Additionally, the excellent nanoporous structure constructed promotes the penetration of the electrolyte and the release of the product. Thus, The CoFe-P@MXene-based electrocatalyst exhibits excellent OER catalytic performance at both low current densities and industrial-scale current densities, with remarkable low overpotentials of 215 mV at 20 mA cm-2 and 328 mV at 1000 mA cm-2 in 1 M KOH solution, respectively. Furthermore, it exhibits good stability, capable of operating stably for 100 h at a current density of 100 mA cm-2. This work highlights the promising application of MXene-based electrocatalyst with multiple heterojunctional structure for industrial-scale water splitting.

Highly efficiency, excellent stability and low-cost catalysts equipping with uniform distribution and enough active sites are rather important for zinc-air batteries (ZABs). In this study, inspired by hollow bubble structured...

BiOCl is a promising photocatalyst, but due to its weak visible light absorption capacity and low photogenerated electron-hole pair separation rate, its practical application is limited to a certain extent. In this study, a novel double Z-scheme heterojunction UiO-66-NH2/BiOCl/Bi2S3 catalyst was constructed to broaden the visible light response range and promote high photogenerated hole-electron separation of BiOCl. Its photocatalytic performance is evaluated by dissociating tetracycline (TC) and rhodamine B (RhB) in visible light. The optimal proportion of UiO-66-NH2/BiOCl/Bi2S3 hybrids exhibits the best degradation efficiency of visible light illumination (∼93% in 120 min for TC and ∼98% in 60 min for RhB). The synergistic effect of a large visible light response range and the Z-scheme charge transfer mechanism ensure the excellent visible photocatalytic activity of UiO-66-NH2/BiOCl/Bi2S3. It is proven that h+ and •O2- are the main active substances in the photocatalysis process by active substance capture experiments and electron spin resonance tests. The intermediates and degradation processes are analyzed by high-performance liquid chromatography-mass spectrometry. This study proves that the new UiO-66-NH2/BiOCl/Bi2S3 photocatalyst has great application potential in the field of water pollution degradation and will provide a new idea for the optimization of BiOCl.

Developing high-efficient, good-durability, and low-cost bifunctional non-precious metal catalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is urgent and significant for promoting the practical rechargeable zinc-air batteries (RZABs). Herein, N-doped carbon coated Co/FeCo@Fe(Co)3O4 heterojunction rich in oxygen vacancies derived from metal-organic frameworks (MOFs) is successfully constructed by O2 plasma treatment. The phase transition of Co/FeCo to FeCo oxide (Fe3O4/Co3O4) mainly occurs on the surface of nanoparticles (NPs) during the O2 plasma treatment, which can form rich oxygen vacancies simultaneously. The fabricated catalyst P-Co3Fe1/NC-700-10 with optimal O2 plasma treatment time of 10 min can reduce the potential gap between the OER and ORR to 760 mV, which is much lower than commercial 20% Pt/C + RuO2 (910 mV). Density functional theory (DFT) calculation indicates that the synergistic coupling between Co/FeCo alloy NPs and FeCo oxide layer can promote the ORR/OER performance. Both liquid electrolyte RZAB and flexible all-solid-state RZAB using P-Co3Fe1/NC-700-10 as the air-cathode catalyst display high power density, specific capacity and excellent stability. This work provides an effective idea for the development of high performance bifunctional electrocatalyst and the application of RZABs.

Abstract The development of catalysts that are optically transparent, electrically charge‐transferable, and capable of protecting underlying photoactive semiconductors is crucial for efficient photoelectrochemical (PEC) hydrogen production. However, meeting all these requirements simultaneously poses significant challenges. In this study, the fabrication of a wafer‐scale transparent bilayer MoS2/WS2 catalyst is presented with a staggered heterojunction, optimized for photon absorption, extraction of photogenerated charge carriers, and surface passivation of p‐Si photocathode. The MoS2 and WS2 monolayers are grown via metal‐organic chemical vapor deposition, followed by sequential transfer and stacking onto the p‐Si photocathode. The resulting type‐II heterojunction film establishes a strong built‐in electric field for rapid charge carrier transport and effectively protects the Si surface from oxidation and corrosion. The fabricated MoS2/WS2/p‐Si photocathode demonstrates outstanding PEC performance, achieving a high photocurrent density of −25 mA cm−2 at 0 V versus reversible hydrogen electrode, along with enhanced stability compared to monolayer MoS2/p‐Si. This work provides promising strategies for developing optically transparent, electrically active, and protective catalysts for practical PEC energy conversion systems.

Summary Layered double hydroxides (LDHs) are widely used in catalytic field, especially in photocatalysis, benefiting from the ultrathin 2D structure and luxuriant surface functional groups. However, the wide band gap and low utilization rate of solar spectrum affect their photocatalytic performance. Herein, we integrated n-type CoAl-LDH with p-type Cu2O nanoparticles to construct a p-n heterojunction with a strong built-in electric field, which can prevent photoinduced electron-hole pairs from recombination as well as facilitate charge transfer. With the X-ray photoelectron spectroscope and in situ Fourier transform infrared spectroscopy, we confirmed the charge transfer under light illumination complying with the type II-scheme mechanism and analyzed the intermediates during photocatalytic CO2 reduction reaction (CO2RR). The highest yields reached 320.9 μmol h−1 g−1 for CoAl-LDH@Cu2O-60 (LC-60) under 1 h light irradiation, which was about 1.6 times than the pristine CoAl-LDH. The sample also exhibited excellent stability which maintained 84.1% of initial performance after 4 circulations.

The efficient hydrogenation of biomass-derived levulinic acid (LA) to value-added γ-valerolactone (GVL) based on nonprecious metal catalysts under mild conditions is crucial challenge because of the intrinsic inactivity and instability of these catalysts. Herein, a series of highly active and stable carbon-encapsulated Co/ZnO@C-X (where X = 0.1, 0.3, 0.5, the molar ratios of Zn/(Co+Zn)) heterojunction catalysts were obtained by in situ pyrolysis of bimetal CoZn MOF-74. The optimal Co/ZnO@C-0.3 catalyst could achieve 100% conversion of LA and 98.35% selectivity to GVL under mild conditions (100 °C, 5 bar, 3 h), which outperformed most of the state-of-the-art catalysts reported so far. Detailed characterizations, experimental investigations, and theoretical calculations revealed that the interfacial interaction between Co and ZnO nanoparticles (NPs) could promote the dispersibility and air stability of the active Co0 for the activation of H2. Moreover, the strong Co-ZnO interaction also enhanced the Lewis acidity of the Co/ZnO interface, contributing to the adsorption of LA and the esterification of intermediates. The synergy between the hydrogenation sites and the Lewis acid sites at the Co/ZnO interface enabled the conversion of LA to GVL with high efficiency. In addition, benefiting from the Co-ZnO interfacial interaction as well as the unique carbon-encapsulated structure of the heterojunction catalyst, the recyclability was also greatly improved and the yield of GVL was nearly unchanged even after six cycles.

The development of photocatalysts with a wide spectral response and effective carrier separation capability is essential for the green degradation of tetracycline hydrochloride. In this study, a magnetic recyclable Z-scheme ZnO/ZnFe2O4 heterojunction (ZZF) was successfully constructed via the solid phase method, using MIL-88A(Fe)@Zn as the precursor. An appropriate band gap width and Z-scheme charge transfer mechanism provide ZZF with excellent visible light absorption performance, efficient charge separation, and a strong redox ability. Under visible light irradiation, the degradation efficiency of tetracycline hydrochloride for the optimal sample can reach 86.3% within 75 min in deionized water and 92.9% within 60 min in tap water, exhibiting superior stability and reusability after five cycles. Moreover, the catalyst in the water can be conveniently recovered by magnetic force. After visible light irradiation for 70 min, the temperature of the reaction system increased by 21.9 °C. Its degradation constant (35.53 × 10−3 min−1) increased to 5.1 times that at room temperature (6.95 × 10−3 min−1). Using thermal energy enhances the kinetic driving force of the reactants and facilitates carrier migration, meaning that more charge is available for the production of •O2− and •OH. This study provides a potential candidate for the efficient degradation of tetracycline hydrochloride by combining thermal catalysis with a photocatalytic heterojunction.

Photocatalytic CO2 reduction technology has engaged significant attention due to its high efficiency, high selectivity, and environmental friendliness. However, its application is severely restrained by issues such as low separation efficiency of photogenerated carriers and a limited light absorption range. This work proposes an innovative MgCr2O4/MgIn2S4 magnesium-based spinel/spinel heterostructure photocatalyst to improve the photocatalytic CO2 reduction efficiency through the synergistic contributions of S-scheme heterojunction and photothermal effect. On the one hand, the unique S-scheme charge transfer mechanism enables the effective separation of photogenerated carriers. On the other hand, the photothermal effect allows an accelerated charge migration by increasing the reaction center temperature. Moreover, the abundant oxygen vacancies serve as electron traps and CO2 adsorption sites, unifying reaction and adsorption sites and substantially improving catalytic efficiency. Under UV-vis and UV-vis-NIR illumination, the average CO yields of the MgCr2O4/MgIn2S4 composite are 8.03 and 15.62 μmol g-1 h-1, respectively, greatly higher than those of pure MgCr2O4 and MgIn2S4 samples. Furthermore, the fabricated photocatalyst demonstrates excellent performance and structure stability. Therefore, this work may offer a new strategy for designing efficient and stable photocatalysts.

The catalytic conversion of biomass-derived furfural (FFA) to cyclopentanone (CPO) in aqueous solution is an important pathway to obtain sustainable resources, however, the conversion and selectivity under mild conditions are still unsatisfactory. Herein, a catalyst that is made of Ni-NiO heterojunction supported by TiO2 with optimized composition of anatase and rutile (Ni-NiO/TiO2-Re450) was facilely prepared by pyrolysis at 450 °C. By using Ni-NiO/TiO2-Re450, complete conversion of FFA and 87.4% of CPO yield can be achieved under mild reaction conditions (1 MPa, 140 °C, 6 h). The FFA conversion was kept at 95.4% in the fifth run, indicating the high stability of the catalyst.Multiple characterizations, control experiments, and theoretical calculation demonstrate that the high catalytic performance of Ni-NiO/TiO2-Re450 mainly attributes to the synergistic effect of Ni-NiO heterojunction and the TiO2 support. This low-cost catalyst may expedite the catalytic upgrading and practical application of biomass-derived chemicals.

Amid increasing fossil energy scarcity, a key solution is using solar energy to split water into hydrogen (H2). However, single photocatalysts face limitations of low solar utilization rate and rapid carrier recombination, so constructing novel composite photocatalysts is a promising solution. Here, a novel ZnO/UiO‐66‐NH2@ZnIn2S4 (ZUN@ZIS) composite catalyst with twin S‐scheme heterojunction is constructed for the first time, in which ZnIn2S4 (ZIS) nanosheets are grown in situ on the surface of ZnO/UiO‐66‐NH2 (ZUN) rhombic octahedra. Under the irradiation of visible light and without the help of any co‐catalyst, the H2 evolution rate of the prepared ZUN@ZIS‐20 is 5.05 mmol g−1 h−1, which is 3.7, 2.1 and 46 times higher than that of ZIS, UiO‐66‐NH2/ZIS (UN/ZIS) and ZUN, respectively. Moreover, the synergistic effect of the resulting ZUN@ZIS twin S‐scheme heterojunction facilitates the provision of efficient channels for carrier/mass transfer and ensures structural stability. Various experimental characterizations and theoretical calculations confirm that the twin S‐scheme heterojunction constructed by ZUN and ZIS can facilitate the easy separation and transfer of photogenerated carriers. This study has developed a new idea for the efficient H2 evolution of multi‐heterojunction photocatalysts, and provided a valuable reference for the development of H2 energy in photocatalysis technology.

The oxidative degradation of plastics in conjunction with the production of clean hydrogen (H2) represents a significant challenge. Herein, a Ni3S4/ZnCdS heterojunction is rationally synthesized and employed for the efficient production of H2 and high‐selectivity value‐added chemicals from waste plastic. By integrating spectroscopic analysis techniques with density functional theory (DFT) calculations, a solely electron transfer‐mediated reaction mechanism is confirmed, wherein Ni3S4 extracts electrons from ZnCdS (ZCS) to promote the spatial segregation of photogenerated electrons and holes, which not only facilitates H2 production but also maintains the high oxidation potential of holes on the ZCS surface, favoring hole‐dominated plastic oxidation. Notably, the catalyst exhibited efficient H2 production rates as high as 27.9 and 17.4 mmol g−1 h−1, along with a selectivity of 94.2% and 78.3% in the liquid product toward pyruvate and acetate production from polylactic acid (PLA) and polyethylene terephthalate (PET), respectively. Additionally, carbon yields of 26.5% for pyruvate and 2.2% for acetate are measured after 9 h of photoreforming, representing the highest values reported to date. Overall, this research presents a promising approach for converting plastic waste into H2 fuel and high‐selectivity valuable chemical products, offering a potential solution to the growing issue of “White Pollution”.

The practical application of photocatalytic H2-evolution is greatly limited by its sluggish charge separation, insufficient active sites, and stability of photocatalysts. Zero-dimensional (0D) Ti3C2 MXene quantum dots (MQDs) and amorphous Ti(IV) have been proven to be potential substitutes for noble co-catalyst to accelerate the separation of photogenerated electron-hole pairs and prevent the self-oxidation of photocatalysts, leading to better photocatalytic H2-evolution performance with long-term stability. In this study, amorphous Ti(IV) and MQDs co-catalysts were successfully deposited on ZnIn2S4 (ZIS) microspheres composed of ultra-thin nanosheets via a simple impregnation and self-assembly method (denoted as MQDs/ZIS/Ti(IV)). As expected, the optimal MQDs/ZIS/Ti(IV) sample exhibited a photocatalytic H2-evolution rate of 7.52 mmol·g−1·h−1 and excellent photostability without metallic Pt as the co-catalyst in the presence of Na2S/Na2SO3 as hole scavenger, about 16, 4.02 and 4.25 times higher than those of ZIS, ZIS/Ti(IV), and MQDs/ZIS, respectively. The significantly enhanced photocatalytic H2-evolution activity is attributed to the synergistic effect of the three-dimensional (3D) flower-like microsphere structure, the amorphous Ti(IV) hole co-catalyst, and a Schottky junction formed at the ZIS–MQDs interface, which offers more active sites, suppresses self-photocorrosion, and photo-generates the charge recombination of ZIS.

The construction of heterojunctions is considered to be an important means to promote efficient electron-hole separation in photocatalysts. However, photocatalysts have poor light absorption ability and a relatively small chance of capturing H+, and the stability needs to be improved. In this work, a non-precious metal co-catalyst Cu3P was introduced for the successful construction of p-n heterojunctions from NiO and CdS to promote charge separation while expanding the light absorption capacity and increasing the chance of H+ capture, thus enhancing the photocatalytic hydrogen precipitation activity and stability. The overall photocatalytic performance was improved by continuously optimizing the loading of NiO and Cu3P. Satisfyingly, using a 5 W LED lamp as the light source, the hydrogen evolution rate of the composite photocatalyst 15NC@Cu-10 in 10 vol% lactic acid solution is 15 612.0 μmol h-1 g-1, and the AQE reaches 10.4%. XPS analysis confirmed the direction and path of electron transfer. This synergistic strategy of co-catalyst modification of p-n heterojunctions provides a unique insight into the preparation of efficient and stable photocatalysts and also expands the applications of MOFs and their derivatives in the field of photocatalysis.

Iron-based heterogeneous catalysts are ideal metal catalysts owing to their abundance and low-toxicity. However, conventional iron nanoparticle catalysts exhibit extremely low activity in liquid-phase reactions and lack air stability. Previous attempts to encapsulate iron nanoparticles in shell materials toward air stability improvement were offset by the low activity of the iron nanoparticles. To overcome the trade-off between activity and stability in conventional iron nanoparticle catalysts, we developed air-stable iron phosphide nanocrystal catalysts. The iron phosphide nanocrystal exhibits high activity for liquid-phase nitrile hydrogenation, whereas the conventional iron nanoparticles demonstrate no activity. Furthermore, the air stability of the iron phosphide nanocrystal allows facile immobilization on appropriate supports, wherein TiO2 enhances the activity. The resulting TiO2-supported iron phosphide nanocrystal successfully converts various nitriles to primary amines and demonstrates high reusability. The development of air-stable and active iron phosphide nanocrystal catalysts significantly expands the application scope of iron catalysts.

Catalysts with S-scheme semiconductor junctions offers an enhanced redox capacity. Herein, BiOBr/Ag/Ag2S composites with a three-dimensional structure were prepared by hydrothermal reaction. The growth of Ag2S nanoparticles on the surface of BiOBr nanoflowers was successfully achieved, leading to strong light absorption and surface plasmon resonance (SPR) effect, together with improved rates of light-induced carriers. In the presence of peroxymonosulfate (PMS), the BiOBr/Ag/Ag2S composite removed 90.1 % of tetracycline (TC), outperforming BiOBr or Ag/Ag2S, owing to its superior redox capability and reduced carrier recombination efficiency. Additionally, BiOBr/Ag/Ag2S demonstrated excellent recovery performance and stability. Liquid chromatography-mass spectrometry (LC-MS) was employed to investigate the possible intermediate products and reaction pathways. The reaction mechanism of the S-scheme semiconductor heterojunction was further elucidated through density functional theory (DFT) calculations. In conclusion, the research provides a novel approach to activate PMS using an S-scheme semiconductor heterojunction with high redox capacity for practical use in wastewater treatment.

The rapid complexation of photogenerated electrons-holes with copper (Cu) greatly limits the large-scale application of cuprous oxide (Cu2O) as a photocatalyst. Therefore, using a hydrothermal method, a type Ⅱ heterojunction structure was constructed by modifying Cu2O with cerium (IV) oxide (CeO2). The CeO2/Cu2O heterojunction photocatalyst effectively increased the photogenerated electron density and reduced the surface transfer impedance. The improved separation of photogenerated electron-hole pairs resulted in excellent photocatalytic activity. Consequently, the sulfadiazine (SDZ) degradation rate by CeO2/Cu2O reached 87.5%. Furthermore, after five cycles, the SDZ degradation rate remained as high as 78.5%, demonstrating the good stability of CeO2/Cu2O. The SDZ degradation intermediates were analyzed using high-performance liquid chromatography-tandem mass spectrometry, and possible degradation pathways were proposed. Trapping agent experiments, and energy band structure calculations revealed that CeO2/Cu2O photocatalyzes SDZ degradation via a type Ⅱ heterojunction charge transfer mechanism. Finally, the total organic carbon showed that SDZ eventually decomposed to CO2 and H2O, with complete SDZ degradation. This study provides a reference for the preparation of visible light-responsive photocatalysts.

Hydrogen energy is considered to be a critical environmentally friendly and widely sourced renewable energy source that can be used as an alternative to fossil fuels. At present, the preparation of hydrogen (H2) mainly depends on traditional fossil fuels. In order to achieve sustainable development of environmental protection, great attention has been paid to the preparation of H2 by electrocatalysis, photocatalysis, and photoelectrochemistry. Here, it is reported for the first time that a novel active catalyst for the hydrogen evolution reaction, consisting of all‐2D amorphous nanosheets/2D crystal layer heterojunction structure and without any noble metal (no precious metals are present in the preparation or measuring), is almost entirely fabricated by laser ablation in liquid (LAL) growth of amorphous cobalt sulfide on the surface of multilayered molybdenum disulfide. In acidic media, the amorphous cobalt sulfide nanosheets/multilayered molybdenum disulfide (a‐CoS/MoS2) catalyst exhibits fast hydrogen evolution kinetics with onset potential of −147 mV and a Tafel slope of 126 mV per decade, which is much better than only the amorphous cobalt sulfide and molybdenum disulfide layer. The high hydrogen evolution activity of the amorphous cobalt sulfide nanosheets/multilayered molybdenum disulfide hybrid is likely due to the unique electrocatalytic synergistic effects between hydrogen evolution‐active amorphous cobalt sulfide nanosheets and layered crystal molybdenum disulfide materials, as well as the much‐increased catalytic sites. This work provides a new general route based on all‐2D amorphous nanosheets/2D crystal structure for designing and preparing novel layered materials with effectively manipulated catalytic properties and active functionality surface.

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The shocking increase of resistant dye pollutants in the environment and their harmful effects has become a potential threat to the ecosystem. In the current work, the novel and highly efficient potato-on-rod-like Z-scheme plasmon Ag2CrO4-Ag2Mo2O7 heterojunction nano-photocatalyst was synthesized by precipitation method to photodegrade different organic dyes under artificial sunlight. The required analysises were carried out to characterize nanophotocatalysts. FESEM and TEM results showed the placement way of potato-like Ag2CrO4 between/on rod-like Ag2Mo2O7 which was leading to suitable structure and surface morphology. Besides, the morphology observations released the meso-/macroporous potato-on-rod like architecture self-assembled by nanoparticles. DRS analysis also confirmed two band gap energies of 2.55 and 1.72 eV in Ag2CrO4-Ag2Mo2O7 (3:1) resulting from forming a heterojunction structure and the plasmon Ag. Ag2CrO4-Ag2Mo2O7 (3:1) nanophotocatalyst exhibited the most remarkable activity in the photodegradation of 10 mg/L 2-naphthol orange (97.8%), 10 mg/L rhodamine B (99.7%), 10 mg/L crystal violet (98.9%), and 10 mg/L methyl orange (56.1%) with a catalyst dosage of 0.1 gr for about 90 min. The appropriate energy band gap, the formation of the heterostructure, the presence of meso (0.0038 cm3/g) and macro (0.0044 cm3/g) holes, and pore diameter at about 17.2 nm based on BET-BJH analysis that facilitated the penetration of pollutant molecules, increased pollutant adsorption and demonstrated stunning capability of efficient light harvesting, the reason was electron-hole pairs recombination rate reduction. Moreover, the fabricated samples showed tremendous catalyst constancy and reusability even after the fourth run. Results have shown the remarkable photocatalytic activity under visible light and provide an environment-friendly and green strategy to overcome the challenges of organic pollutants present in aqueous solutions.

A heterojunction catalyst, BiVO4/P25, was successfully fabricated using a one-step hydrothermal method. The prepared composite was characterized using XRD, XPS, Raman, FT-IR, UV–vis, SEM, HRTEM and PL. The HRTEM pictures revealed that the heterostructured composite was composed of BiVO4 and P25, and from the pictures of SEM we could see the P25 nanoparticles assembling on the surface of flower-shaped BiVO4 nanostructures. The XPS spectra showed that the prepared catalyst consisted of Bi, V, O, Ti and C. The photocatalytic activity of BiVO4/P25 was evaluated by degraded methyl blue (MB) and tetracycline under visible light illumination (λ > 420 nm), and the results showed that BiVO4/P25 composite has a better photocatalytic performance compared with pure BiVO4 and the most active c-BiVO4/P25 sample showed enough catalytic stability after three successive reuses for MB photodegradation. The enhanced photocatalytic performance could mainly be attributed to the better optical absorption ability and good absorption ability of organic contaminants.

Transition metal phosphorus (TMPs) and sulfides have attracted extensive attention as important candidates to replace noble metal-based hydrogen evolution (HER) catalysts. However, the insufficient specific surface area, low conductivity and easy detachments from electrode seriously affect the HER catalytic activity and stability. Herein, a novel self-supported hollow Janus-structured NiCoP/P-MoS2 heterojunction is designed on carbon cloth (CC) as high-performance electrocatalyst for alkaline HER. The binder-free NiCoP/P-MoS2/CC electrode with well-dispersed hollow structure exhibits acceptable durability and low overpotential, which requires overpotential of 52.6 mV to reach 10 mA cm-2, far superior to that of NiCoP/CC (111.2 mV), P-MoS2/CC (213.3 mV) electrode and also the corresponding NiCoP/P-MoS2 powder catalyst (113.1 mV). Experimental and theoretical results confirm that heterointerface interaction can improve the electronic state, accelerate charge transfer and optimize hydrogen adsorption energy, resulting in boosted HER kinetic process. Additionally, self-supported strategy is conducive to tightly anchoring high-quality active substances with well-organized hollow array structure, which significantly prevents the catalyst agglomeration and shedding, leading to the improved HER stability. This work offers valuable insights into the catalytic mechanisms and provides an avenue for designing hierarchical architecture for highly efficient and stable HER electrocatalysts.