有机无机铅卤钙钛矿光催化剂制氢和二氧化碳还原的综述

ConspectusThe conversion of solar energy into chemical fuels via photocatalytic water splitting represents a promising pathway to sustainable hydrogen production. Halide perovskites (HPs) have emerged as remarkable photocatalysts owing to their strong visible-light absorption, tunable bandgaps, long carrier diffusion lengths, and defect-tolerant electronic structures. The photocatalytic hydrogen evolution in aqueous solution was first reported in 2016, wherein the inherent aqueous instability of HPs was addressed through a dissolution-precipitation dynamic equilibrium between the halide perovskite (HP) powders and HP-saturated hydroiodic acid (HI) solution. Early systems, however, faced fundamental limitations: (1) limited charge utilization due to the high carrier recombination and insufficient surficial reactive sites; (2) restriction to the hydrogen evolution half-reaction in concentrated HI solution, which was an uneconomical material source and also caused thermodynamic inefficiency for I- oxidation instead of water splitting.Over the past decade, our research has focused on addressing these challenges through a combination of material- and system-level innovations. On the materials side, we have explored cocatalyst loading, heterostructure and composite construction, and compositional tuning at the A-, B-, and X-sites to improve carrier utilization efficiency and accelerate surface reaction kinetics, thereby improving photocatalytic performance. These efforts have enabled solar-to-hydrogen (STH) conversion efficiencies exceeding 5% for HI splitting and set the foundation for further advancements. At the system level, we pioneered a solar-driven decoupled water-splitting platform by integrating HP-based photocatalytic hydrogen evolution with spatially separated electrocatalytic or photoelectrocatalytic water oxidation via an I3-/I- redox shuttle. This design resolved critical issues of instability and thermodynamic limitation of HPs for direct water splitting, enabling sustained and stoichiometric hydrogen and oxygen evolution. Building on this, we introduced hydrolytically stable HPs through organic macromolecule incorporation and paired them with complementary oxygen evolution photocatalysts to establish Z-scheme configurations operating in mildly acidic media. Together, these advances in HP-based systems have enabled solar-driven overall water splitting, with STH efficiencies exceeding 2%.This Account summarizes the evolution of HP photocatalysis from early sacrificial hydrohalic acid splitting to integrated solar-driven overall water splitting, highlighting the interplay between material modifications and system designs in overcoming key bottlenecks. We conclude by discussing persistent challenges, including long-term stability, morphology and particle-size control, and interfacial charge management, while outlining future research directions toward translating laboratory advances into practical and scalable solar hydrogen production.

Photocatalytic H2 evolution from haloid acid (HX) solution by metal halide perovskites (MHPs) has been intensively investigated; however, the corrosive acid solution severely restricts its practical operability. Therefore, developing acid-free schemes for H2 evolution using MHPs is highly desired. Here, we investigate the photocatalytic anaerobic dehydrogenation of alcohols over a series of MHPs (APbX3, A = Cs+, CH3NH3+ (MA), CH(NH2)2+ (FA); X = Cl-, Br-, I-) to simultaneously produce H2 and aldehydes. Via the coassembly of Pt and rGO nanosheets on MAPbBr3 microcrystals, the optimal MAPbBr3/rGO-Pt reaches a H2 evolution rate of 3150 μmol g-1 h-1 under visible light irradiation (780 nm ≥ λ ≥ 400 nm), which is more than 105-fold higher than pure MAPbBr3 (30 μmol g-1 h-1). The present work not only brings new ample opportunities toward photocatalytic H2 evolution but also opens up new avenues for more effective utilization of MHPs in photocatalysis.

Solar hydrogen conversion represents a clean and economic approach to addressing global energy and environmental issues, for which efficient photocatalysts are heavily pursued. Lead halide perovskites are promising candidates for efficient phtocatalysts in solar hydrogen generation due to their attractive properties in light absorption, photogenerated charge transportation, and utilization. However, photocatalytic applications of lead halide perovskites are limited owing to their poor stability in the presence of water or other polar solvent environment. This work presents the rational control of surface ligands in achieving a good balance between stability and photocatalytic activity of CsPbBr3 quantum dots (QDs). Detailed studies reveal that the deliberate surface ligands engineering is crucial for maximizing the photocatalytic activity of CsPbBr3 QDs while maintaining good QD stability. A certain amount of surface ligands protect the CsPbBr3 QDs from decomposition in moisture during the photocatalytic reaction while still enabling efficient charge transfer for photocatalytic reactions on the surface of QDs. The well‐controlled CsPbBr3 photocatalyst shows efficient visible light‐driven H2 generation with outstanding stability (≥160 h).

The need to constrain the use of fossil fuels causing global warming is motivating the development of a variety of photocatalysts for solar‐to‐fuel generation and chemical synthesis. In particular, semiconductor‐based photocatalysts have been extensively exploited in solar‐driven organic synthesis, carbon dioxide (CO2) conversion into value‐added products, and hydrogen (H2) generation from water (H2O) splitting. Recently, metal halide perovskites (MHPs) have emerged as an important class of semiconductors for heterogeneous photocatalysis owing to their interesting properties. Despite key issues with long‐term stability and degradation in polar solvents due to their ionic character, there has been significant progress in halide perovskite‐based photocatalysts with improving their stability and performance in the gas and liquid phases. This review discusses the state‐of‐the‐art for using halide perovskite‐based photocatalysts and photoelectrocatalysis in hydrogen production from water and halogen acid solutions, CO2 reduction into value‐added chemicals, and various organic chemical transformations. The different types of halide perovskites used, design strategies to overcome the instability issues in polar solvents, and the efficiencies achieved are discussed. Furthermore, the outstanding challenges associated with the use of polar electrolytes and how the stability and performance can be improved are discussed.

Photocatalytic hydrogen generation paves a promising way to mitigate the global energy crisis and deteriorative environmental issues. Among different materials, metal halide perovskites (MHPs) have recently emerged as a promising class of inexpensive and easy‐to‐make semiconductors for various photocatalytic applications such as organic contaminant degradation, CO2 reduction, H2 evolution, and N2 fixation. Although MHPs‐based standalone photocatalysts offer architectural simplicity, they provide restricted control over recombination processes and spatial separation of redox half‐reactions. Meanwhile, heterojunction systems are of growing interest due to their ability to control energy‐consuming redox processes and effectively suppress charge carrier recombination. In this review, the authors elaborately discuss perovskite‐based heterojunction photocatalysts for hydrogen generation both from a material chemistry point of view and band alignment perspective. They discuss the design principle of MHP heterostructures necessary for H2 evolution and the underlying photo‐physics behind process optimization. Moving forward, they conclude by meticulously outlining the ongoing challenges, opportunities, and future outlooks for MHP‐based heterojunction photocatalysts for H2 evolution.

The development of green, sustainable, and economical chemical processes represents a cornerstone challenge within chemistry today. Semiconductor heterogeneous photocatalysis is currently utilized ...

Solar driven hydrogen generation is one of the promising technologies to a address the world’s growing energy demand in an sustainable way. While, for hydrogen generation (otherwise water splitting), photocatalytic, photoelectrochemical and PV-integrated water splitting systems employing conventional semiconductor oxides materials and their electrodes are under investigation over a decade, lead (Pb)- halide perovskites (HPs) made their debut in 2016. Since then, the exceptional characteristics of these materials, such as their tunable optoelectronic properties, ease of processing, high absorption coefficients, and long diffusion lengths, have positioned them as a highly promising material for solar-driven water splitting. Like in solar photovoltaics, in solar driven water splitting field is also dominated by Pb-HPs with on-going efforts to improve the material stability and improving the hydrogen evolution/generation rate (HER). Despite this, with the unveiling potential of various Pb-free HP compositions in the photovoltaics and optoelectronics inspired researchers to explore the potential of these materials in water splitting. In this current review, we outlined the fundamentals of the water splitting, summary of Pb HPs in this field and the associated issues are presented. Subsequently, Pb-free HPs compositions and strategies employed for improving the photocatalytic and/or electrochemical activity of the material are discussed in detail. Finally, this review presents existing issues and future potential of lead-free HPs, which show potential for enhancing productivity of solar-to-hydrogen conversion technologies.

A growing number of research articles have been published on the use of halide perovskite materials for photocatalytic reactions. These articles extend these materials’ great success from solar cells to photocatalytic technologies such as hydrogen production, CO2 reduction, dye degradation, and organic synthesis. In the present review article, we first describe the background theory of photocatalysis, followed by a description on the properties of halide perovskites and their development for photocatalysis. We highlight key intrinsic factors influencing their photocatalytic performance, such as stability, electronic band structure, and sorption properties. We also discuss and shed light on key considerations and challenges for their development in photocatalysis, such as those related to reaction conditions, reactor design, presence of degradable organic species, and characterization, especially for CO2 photocatalytic reduction. This review on halide perovskite photocatalysts will provide a better understanding for their rational design and development and contribute to their scientific and technological adoption in the wide field of photocatalytic solar devices.

To alleviate photoinduced charge recombination in semiconducting nanomaterials represents an important endeavor toward high‐efficiency photocatalysis. Here a judicious integration of piezoelectric and photocatalytic properties of organolead halide perovskite CH3NH3PbI3 (MAPbI3) to enable a piezophotocatalytic activity under simultaneous ultrasonication and visible light illumination for markedly enhanced photocatalytic hydrogen generation of MAPbI3 is reported. The conduction band minimum of MAPbI3 is higher than hydrogen generation potential (0.046 V vs normal hydrogen electrode), thereby rendering efficient hydrogen evolution. In addition, the noncentrosymmetric crystal structure of MAPbI3 enables its piezoelectric properties. Thus, MAPbI3 readily responds to external mechanical force, creating a built‐in electric field for collective piezophotocatalysis as a result of effective separation of photogenerated charge carriers. The experimental results show that MAPbI3 powders exhibit superior piezophotocatalytic hydrogen generation rate (23.30 µmol h−1) in hydroiodic acid (HI) solution upon concurrent light and mechanical stimulations, much higher than that of piezocatalytic (i.e., 2.21 µmol h−1) and photocatalytic (i.e., 3.42 µmol h−1) hydrogen evolution rate as well as their sum (i.e., 5.63 µmol h−1). The piezophotocatalytic strategy provides a new way to control the recombination of photoinduced charge carriers by cooperatively capitalizing on piezocatalysis and photocatalysis of organolead halide perovskites to yield highly efficient piezophotocatalysis.

Photocatalytic hydrogen production, which directly converts solar energy into green chemical fuel, has received widespread attention. However, despite significant efforts, the efficiency of conventional photocatalytic materials remains below industrial requirements,...

Abstract Metal halide perovskite photocatalysts (MHPPs) exhibit unique electronic and optical properties, making them attractive for diverse photocatalytic applications. Their exceptional properties can be tuned by adjusting the halide ion or cation size. MHPPs have shown promise in solar energy conversion, water splitting, and air purification. However, synthesis and stability challenges hinder practical applications. This comprehensive review presents the properties, applications, and challenges of MHPPs, proposing future research directions. Although dogged by many issues, MHPPs demonstrate remarkable charge separation capabilities, rendering them advantageous in many photocatalytic applications. They offer flexibility through the manipulation of elements, crystal structures, surface chemistry, and morphologies. The review also discusses Type-II, Z-scheme heterojunction, as well as the emerging S-scheme heterojunction, which is a recent, improved alternative. Consolidating current knowledge, this review serves as a valuable resource, providing insights into MHPPs’ potential and guiding further advancements. MHPPs have significant applications in water splitting, air purification, pollutant degradation, and energy conversion. Their unique properties and versatility enable tailored optimization. This overview is a crucial reference for researchers, engineers, scholars, and students, inspiring innovative and sustainable photocatalytic solutions.

Abstract Three‐dimensional (3D) organic–inorganic hybrid perovskites have demonstrated excellent capability in solar fuel production, while the two‐dimensional (2D) counterparts are generally considered inferior candidates due to the high exciton binding energy and weak light absorption. Herein, contrary to our common understanding, we find that 2D perovskites can perform photocatalytic H 2 production from HI splitting more efficiently than their 3D counterparts. We observed sharp difference between 2D perovskites crystals with organic phenylalkylammonium cations of different lengths and the 3D counterparts in their stabilization behavior in aqueous solution. Moreover, we show that the organic cations length of the 2D perovskites affects the nanostructures, optoelectronic properties, and the charge transfer process significantly, which determines the photocatalytic activity of the 2D perovskites. Among the 2D perovskites under investigation, phenylmethylammonium lead iodide with the shortest organic cations achieved the best solar‐to‐chemical conversion efficiency of ca. 1.57 %, which is the highest value ever reported for hybrid perovskites.

Due to its environmental cleanliness and high energy density, hydrogen has been deemed as a promising alternative to traditional fossil fuels. Photocatalytic water-splitting using semiconductor materials is a good prospect for hydrogen production in terms of renewable solar energy utilization. In recent years, halide perovskite nanocrystals (NCs) are emerging as a new class of fascinating nanomaterial for light harvesting and photocatalytic applications. This is due to their appealing optoelectronic properties, such as optimal band gaps, high absorption coefficient, high carrier mobility, long carrier diffusion length, etc. In this review, recent progress in halide perovskite NCs for photocatalytic hydrogen evolution is summarized. Emphasis is given to the current strategies that enhance the photocatalytic hydrogen production performance of halide perovskite NCs. Some scientific challenges and perspectives for halide perovskite photocatalysts are also proposed and discussed. It is anticipated that this review will provide valuable references for the future development of halide perovskite-based photocatalysts used in highly efficient hydrogen evolution.

Abstract Photocatalytic water splitting using semiconductors is a promising approach for converting solar energy to clean energy. However, challenges such as sluggish water oxidation kinetics and limited light absorption of photocatalyst cause low solar‐to‐hydrogen conversion efficiency (STH). Herein, we develop a photocatalytic overall water splitting system using I 3 − /I − as the shuttle redox couple to bridge the H 2 ‐producing half‐reaction with the O 2 ‐producing half‐reaction. The system uses the halide perovskite of benzylammonium lead iodide (PMA 2 PbI 4 , PMA=C 6 H 5 CH 2 NH 2 ) loaded with MoS 2 (PMA 2 PbI 4 /MoS 2 ) as the H 2 evolution photocatalyst, and the RuO x ‐loaded WO 3 (WO 3 /RuO x ) as the O 2 evolution photocatalyst, achieving a H 2 /O 2 production in stoichiometric ratio with an excellent STH of 2.07 %. This work provides a detour route for photocatalytic water splitting with the help of I 3 − /I − shuttle redox couple in the halide perovskite HI splitting system and enlightens one to integrate and utilize multi catalytic strategies for solar‐driven water splitting.

Using semiconductor photocatalysts to achieve CO2 photoreduction presents a promising approach to solving the environmental and energy crises caused by CO2 emissions. Plasmon–perovskite hybrid photocatalysts for CO2 photoreduction are garnering increasing attention owing to the excellent photoelectric properties of perovskites and the unique localized surface plasmon resonance effect of plasmonic materials. This review summarizes the latest progress and performance of plasmon-enhanced perovskite photocatalysts for photocatalytic CO2 reduction. Simultaneously, the most pivotal mechanisms and other various mechanisms of plasmonic nanoparticles in improving photocatalytic activity were distinguished and analyzed. Finally, a summary of the current challenges and future development directions of these promising plasmon-enhanced perovskite photocatalysts is proposed to advance the development of efficient and sustainable CO2 photoreduction in the field of perovskite photocatalysts.

Photoelectrochemical (PEC) hydrogen/oxygen generation, CO2 reduction, and photocatalytic dye degradation offer promising pathways for sustainable energy production and environmental remediation by utilizing solar energy. Perovskite halides, with their exceptional optoelectronic properties, have garnered significant attention in these applications. This review comprehensively reviews recent developments in using perovskite halides for PEC hydrogen and oxygen evolution reactions, CO2 reduction, and photocatalytic detoxification of water. State-of-the-art achievements in enhancing these performances using various device design engineering and construction strategies for efficient charge transfer in aqueous environments are highlighted. The review continues with the exploration of dimensional/compositional engineering, nanocomposites/heterojunctions, core-shell nanostructures, and functionalization of protective layers to improve the efficiency and water stability of perovskite halides for PEC applications. Furthermore, organic-inorganic, all-inorganic, Pb-free hybrid halide perovskites, metal double halide perovskite, their multilayer nanocomposites, and the tandem configuration of PEC/Perovskite solar cell reported design strategies are reviewed and critically assessed in the context of device performance and durability. Finally, challenges such as material stability, scalability, and toxicological considerations are addressed, alongside future research directions to advance the practical implementation of hybrid perovskite nanomaterials in sustainable energy and environmental applications.

The ability to create perovskite-based heterostructures with desirable charge transfer characteristics represents an important endeavor to render a set of perovskite materials and devices with tunable optoelectronic properties. However, due to similar material selection and band alignment in type-II and Z-scheme heterostructures, it remains challenging to obtain perovskite-based heterostructures with a favorable electron transfer pathway for photocatalysis. Herein, we report a robust tailoring of effective charge transfer pathway in perovskite-based heterostructures via a type-II to Z-scheme transformation for highly efficient and selective photocatalytic CO2 reduction. Specifically, CsPbBr3/TiO2 and CsPbBr3/Au/TiO2 heterostructures are synthesized and then investigated by ultrafast spectroscopy. Moreover, taking CsPbBr3/TiO2 and CsPbBr3/Au/TiO2 as examples, operando experiments and theoretical calculations confirm that the type-II heterostructure could be readily transformed into a Z-scheme heterostructure through establishing a low-resistance Ohmic contact, which indicates that a fast electron transfer pathway is crucial in Z-scheme construction, as further demonstrated by CsPbBr3/Ag/TiO2 and CsPbBr3/MoS2 heterostructures. In contrast to pristine CsPbBr3 and CsPbBr3/TiO2, the CsPbBr3/Au/TiO2 heterostructure exhibits 5.4- and 3.0-fold enhancement of electron consumption rate in photocatalytic CO2 reduction. DFT calculations and in situ diffuse reflectance infrared Fourier transform spectroscopy unveil that the superior CO selectivity is attributed to the lower energy of *CO desorption than that of hydrogenation to *HCO. This meticulous design sheds light on the modification of perovskite-based multifunctional materials and enlightens conscious optimization of semiconductor-based heterostructures with desirable charge transfer for catalysis and optoelectronic applications.

Abstract Metal‐halide perovskites have been explored as photocatalysts for CO 2 reduction. We report that perovskite photocatalytic CO 2 reduction in organic solvents is likely problematic. Instead, the detected products (i.e., CO) likely result from a photoredox organic transformation involving the solvent. Our observations have been validated using isotopic labeling experiments, band energy analysis, and new control experiments. We designed a typical perovskite photocatalytic setup in organic solvents that led to CO production of up to ≈1000 μmol g −1 h −1 . CO 2 reduction in organic solvents must be studied with extra care because photoredox organic transformations can produce orders of magnitude higher rate of CO or CH 4 than is typical for CO 2 reduction routes. Though CO 2 reduction is not likely to occur, in situ CO generation is extremely fast. Hence a suitable system can be established for challenging organic reactions that use CO as a feedstock but exploit the solvent as a CO surrogate.

… Subsequently, they reported that PbS QDs can also be embedded in a hybrid perovskite matrix (Fig. 2f) [43]. Additionally, the epitaxial growth of CsPbX 3 (X = Cl, Br, and I) …

Two-dimensional organic-inorganic hybrid perovskites ( OIHPs) with alternating structure of the organic and inorganic layers have a natural quantum well structure. The difference of dielectric constants between organic and inorganic layers in this structure results in the enhancement of dielectric confinement effect, which exhibits a large exciton binding energy and hinders the separation of electron-hole pairs. Herein, a strategy to reduce the dielectric confinement effect by narrowing the dielectric difference between organic amine molecule and [PbBr6]4- octahedron is put forward. The Ethanolamine (EOA) contains hydroxyl groups, resulting in the positive and negative charge centers of O and H non-overlapping,which generated a larger polarity and dielectric constant. The reduced dielectric constant produces a smaller exciton binding energy (71.03 meV) of (C2H7NO)2PbBr4 ((EOA)2PbBr4) than (C8H11N)2PbBr4 ((PEA)2PbBr4 (156.07 meV), and promotes the dissociation of electrons and holes. The increasing of lifetime of photogenerated carrier in (EOA)2PbBr4 are proved by femtosecond transient absorption spectra. DFT calculations have also indicated that the small energy shift of the total density of states (DOS) between the C/H/N and the Pb/Br in (EOA)2PbBr4 favors the separation of electrons and holes. In addition, this work demonstrates the application of (PEA)2PbBr4 and (EOA)2PbBr4 in the field of photocatalytic CO2 reduction.

… A lead-free Cs 2 SnI 6 perovskite nanocrystal/SnS 2 nanosheet hybrid with a type II structure has … Highly selective photocatalytic CO 2 reduction via a lead-free perovskite/MOF catalyst. …

… CO 2 … photocatalytic CO 2 reduction are critically discussed, offering insights for future research in this realm. This Review aims to illuminate the path toward sustainable photocatalysis, …

Perovskite nanocrystals (PNCs) are promising candidates for solar-to-fuel conversions yet exhibit low photocatalytic activities mainly due to serious recombination of photogenerated charge carriers. Constructing heterojunction is regarded as an effective method to promote the separation of charge carriers in PNCs. However, the low interfacial quality and non-directional charge transfer in heterojunction lead to low charge transfer efficiency. Herein, a CsPbBr3 -CdZnS heterojunction is designed and prepared via an in situ hot-injection method for photocatalytic CO2 reduction. It is found that the high-quality interface in heterojunction and anisotropic charge transfer of CdZnS nanorods (NRs) enable efficient spatial separation of charge carriers in CsPbBr3 -CdZnS heterojunction. The CsPbBr3 -CdZnS heterojunction achieves a higher CO yield (55.8 µmol g-1  h-1 ) than that of the pristine CsPbBr3 NCs (13.9 µmol g-1  h-1 ). Furthermore, spectroscopic experiments and density functional theory (DFT) simulations further confirm that the suppressed recombination of charge carriers and lowered energy barrier for CO2 reduction contribute to the improved photocatalytic activity of the CsPbBr3 -CdZnS heterojunction. This work demonstrates a valid method to construct high-quality heterojunction with directional charge transfer for photocatalytic CO2 reduction. This study is expected to pave a new avenue to design perovskite-chalcogenide heterojunction.

Perovskite materials have been widely considered as emerging photocatalysts for CO2 reduction due to their extraordinary physicochemical and optical properties. Perovskites offer a wide range of benefits compared to conventional semiconductors, including tunable bandgap, high surface energy, high charge carrier lifetime, and flexible crystal structure, making them ideal for high-performance photocatalytic CO2 reduction. Notably, defect-induced perovskites, for example, crystallographic defects in perovskites, have given excellent opportunities to tune perovskites’ catalytic properties. Recently, lead (Pb) halide perovskite and their composites or heterojunction with other semiconductors, metal nanoparticles (NPs), metal complexes, graphene, and metal-organic frameworks (MOFs) have been well established for CO2 conversion. Besides, various halide perovskites have come under focus to avoid the toxicity of lead-based materials. Therefore, we reviewed the recent progress made by Pb and Pb-free halide perovskites in photo-assisted CO2 reduction into useful chemicals. We also discussed the importance of various factors like change in solvent, structure defects, and compositions in the fabrication of halide perovskites to efficiently convert CO2 into value-added products.

Photocatalytic CO2 reduction to generate energy-riching fuels through solar energy provides an attractive route to alleviate the global energy crisis and environmental concerns. Searching for various photocatalysts with high catalytic...

Solar energy is attractive because it is free, renewable, abundant and sustainable. Photocatalysis is one of the feasible routes to utilize solar energy for the degradation of pollutants and the production of fuel. Perovskites and their derivatives have received substantial attention in both photocatalytic wastewater treatment and energy production because of their highly tailorable structural and physicochemical properties. This review illustrates the basic principles of photocatalytic reactions and the application of these principles to the design of robust and sustainable perovskite photocatalysts. It details the structures of the perovskites and the physics and chemistry behind photocatalytic reactions and describes the advantages and limitations of popular strategies for the design of photoactive perovskites. This is followed by examples of how these strategies are applied to enhance the photocatalytic efficiency of oxide, halide and oxyhalide perovskites, with a focus on materials with potential for practical application, that is, not containing scarce or toxic elements. It is expected that this overview of the development of photocatalysts and deeper understanding of photocatalytic principles will accelerate the exploitation of efficient perovskite photocatalysts and bring about effective solutions to the energy and environmental crisis.

Halide perovskite like methylammonium lead iodide perovskite (MAPbI3) with its prominent optoelectronic properties has triggered substantial concerns in photocatalytic H2 evolution. In this work, to attain preferable photocatalytic performance, a MAPbI3/cobalt phosphide (CoP) hybrid heterojunction is constructed by a facile in situ photosynthesis approach. Systematic investigations reveal that the CoP nanoparticle can work as co‐catalyst to not only extract photogenerated electrons effectively from MAPbI3 to improve the photoinduced charge separation, but also facilitate the interfacial catalytic reaction. As a result, the as‐achieved MAPbI3/CoP hybrid displays a superior H2 evolution rate of 785.9 µmol h−1 g−1 in hydroiodic acid solution within 3 h, which is ≈8.0 times higher than that of pristine MAPbI3. Furthermore, the H2 evolution rate of MAPbI3/CoP hybrid can reach 2087.5 µmol h−1 g−1 when the photocatalytic reaction time reaches 27 h. This study employs a facile in situ photosynthesis strategy to deposit the metal phosphide co‐catalyst on halide perovskite nanocrystals to conduct photocatalytic H2 evolution reaction, which may stimulate the intensive investigation of perovskite/co‐catalyst hybrid systems for future photocatalytic applications.

A stable composite photocatalyst, that is, MAPbI3 decorated with Ni3C, is synthesized by a facile surface charge-promoted self-assembly approach and is demonstrated to be a high-efficiency, stable visible-light photocatalyst for H2 evolution in aqueous MAPbI3-saturated HI solution with H3PO2 as a stabilizer. The optimal 15% Ni3C/MAPbI3 suspension under visible illumination displays the hydrogen evolution reaction (HER) rate of 2362 μmol g–1 h–1, which is approximately 55-fold higher than that of MAPbI3 (43 μmol g–1 h–1) and far superior to that of Pt/MAPbI3 (534 μmol g–1 h–1). In particular, the Ni3C/MAPbI3 photocatalyst is ultrastable, showing no obvious decrease of HER activity in a given HER process, that is, 10 runs, one-month storage, and another 10 runs. The origin of the superior performance is proven to be predominantly attributed to the improved capabilities of charge carrier transfer and separation as well as the massive reactive centers on the surface of MAPbI3 by Ni3C decoration, together with...

Abstract Organic-inorganic perovskites like MAPbI3 with excellent optoelectric properties have recently gained concerns in photocatalytic HI splitting. However, their achieved hydrogen evolution reaction (HER) rates are still insufficient. Herein, a 2D few-layer black phosphorus (BP) as cocatalyst was anchored on MAPbI3 via electrostatic coupling. The resultant BP/MAPbI3 is rather stable in HI solution during the whole photoreaction, yielding a superb HER rate of 3742 μmol h−1 g−1 under visible irradiation, which is two orders of magnitude higher than that of MAPbI3-only, far higher than that of MAPbI3/Pt and also shows the advanced HER performance among MAPbI3 based systems. The remarkably boosted HER activity is thoroughly explored by optical/optoelectrochemical measurements, showing that BP can act as an electron promoter to trap electrons derived from MAPbI3 through a type I heterojunction in the interface. This contributes to a new paradigm for high-efficiency photocatalysts by anchoring non-metal cocatalyst onto MAPbI3 for solar energy conversion.

Abstract Hybrid organic-inorganic perovskites have been pursuing for solar/visible-driven H2 evolution from hydrohalic acid (HX) splitting, but their inherent structural stability and performance are still challenging. Herein, we report on a stable hybrid perovskite MAPb(I1−xBrx)3 (x = 0–0.20) obtained by one-pot crystallization in a mixed halide parent solution and its implementation as a newcomer photocatalyst for H2 evolution in aqueous HX solution. MAPb(I1−xBrx)3 is demonstrated to be a superior visible-light-driven photocatalyst for H2 evolution in aqueous HI/HBr solution with no Pt as a cocatalyst. An optimized MAPb(I1−xBrx)3 (x = 0.10) shows a highest H2 evolution rate of 1471 μmol h−1 g−1 under visible light (λ ≥ 420 nm) illumination, which is ˜40 times higher than that of pure MAPbI3, and the dual-halide perovskite is rather stable showing no obvious decrease in the photocatalytic activity over 60 runs (252 h). The perovskite inherent structural stability is further evidenced by XRD, UV–vis spectra and EDS elemental mapping of MAPb(I1−xBrx)3 measured after cycled photocatalytic reaction. The solar HI splitting efficiency of MAPb(I1−xBrx)3 (x = 0.10) is determined as 1.42%. The mechanism behind photocatalytic H2 evolution enhancement is elucidated by the experimental and computational methods.

Although lead halide perovskites are demonstrated to be promising photocatalysts for hydrogen evolution from hydrogen halide splitting, it still remains challenging to fabricate efficient and stable catalysts. Here MoS2 nanoflowers with abundant active sites are assembled with methylammonium lead iodide (MAPbI3) microcrystals to form a new heterostructure. Its hydrogen evolution rate can reach up to about 30 000 μmol g-1 h-1, which is more than 1000-fold higher than pristine MAPbI3 under visible light irradiation (λ ≥ 420 nm). Importantly, the solar HI splitting efficiency reaches 7.35%, one of the highest efficiencies so far. The introduction of MoS2 with proper band alignment and unsaturated species can efficiently promote the charge separation and afford more active sites for H2 production. This finding not only provides a highly efficient and stable photocatalyst for hydrogen evolution but also offers a useful modification strategy on lead halide perovskites.

… for photocatalytic hydrogen iodide (HI) splitting using methylammonium lead iodide (MAPbI 3 … Here we use MAPbI 3 as a photocatalytic material in dynamic equilibrium with aqueous HI …

… photocatalysts of TiO 2 HoMSs with MAPbI 3 for hydrogen production. The hydrogen evolution performance of photocatalysts … –1 of bare MAPbI 3 . It displayed no obvious degradation of …

… from MAPbI 3 to the H + ions in the reaction medium. … The MAPbI 3 /RGO system for photocatalytic hydrogen evolution … reduction in RGOs for photocatalytic activity of MAPbI 3 /RGO …

Metal halide perovskites, such as iodine methylamine lead (MAPbI3), have received extensive attention in the field of photocatalytic decomposition of HI for hydrogen evolution, due to their excellent photoelectric properties. In this paper, a new MAPbI3-based composite, MoC/MAPbI3, was synthesized. The results show that 15 wt% MoC/MAPbI3 has the best hydrogen production performance (38.4 μmol h-1), which is approximately 24-times that of pure MAPbI3 (1.61 μmol h-1). With the extension of the catalytic time, the hydrogen production rate of MoC/MAPbI3 reached 165.3 μmol h-1 after 16 h due to the effective separation and transfer of charge carriers between MoC and MAPbI3, showing excellent hydrogen evolution rate performance under visible light. In addition, the cycling stability of MoC/MAPbI3 did not decrease in multiple 4 h cycle tests. This study used the non-precious metal promoter MoC to modify MAPbI3, and provides a new idea for the synthesis of efficient MAPbI3-based composite catalysts.

Abstract Organic-inorganic perovskites such as iodine methylamine lead (MAPbI3) shows superb photocatalytic prospect in the field of solar energy driven photocatalysis. However, its catalytic performance is insufficient due to serious charge recombination. In this article, 1T-2H MoSe2/MAPbI3 composites were obtained by simple electrostatic adsorption method. The results of photocatalytic hydrogen production showed that 10 wt% 1T-2H MoSe2/MAPbI3 performed the best hydrogen evolution rate of 552.93 μmol·h−1·g−1, which was 23 times than that of pure MAPbI3 (23.13 μmol·h−1·g−1). The long-term cyclic stability test also indicated that 1T-2H MoSe2/MAPbI3 composites have good stability. The excellent hydrogen evolution rate activity is thoroughly investigated by optical/optoelectrochemical measurements, showing that 1T-2H MoSe2 as a co-catalyst can effectively transfer electrons and promote the separation of photogenerated charge. This study provided a reference for further exploration of MAPbI3-based catalysts with excellent catalytic activity.

Recently, hydrogen (H2) production via photocatalytic process has been received enormous attention of the scientific community globally. Perovskite materials such as methyl ammonium lead iodide (MAPbI3) has excellent photovoltaic and photocatalytic properties and may be a promising photocatalyst for H2 production reaction. In this paper, we have designed and synthesized MAPbI3 perovskite embedded graphitic carbon nitride (MAPbI3@g‐C3N4) composite via benign approaches. The phase and crystalline nature was authenticated by powder X‐ray diffractometer. Morphological characteristics of the MAPbI3@g‐C3N4 composite was further checked by scanning electron microscope. The elemental composition and valence states of the MAPbI3@g‐C3N4 was determined by X‐ray photoelectron spectroscopy (XPS). Furthermore, MAPbI3@g‐C3N4 has been explored as photocatalyst for H2 production reaction using hypophosphorous acid (H3PO2) as stabilizing agent. Platinum (Pt) has been used as co‐catalyst. The reasonably good amount of H2 of 21.25 μmol/g was produced using MAPbI3 as photocatalyst. Further, improved H2 amount of 939.4 μmol/g was produced using MAPbI3@g‐C3N4. The MAPbI3@g‐C3N4 exhibited decent H2 production rate of 93.94 μmol/h/g. The excellent stability of the MAPbI3@g‐C3N4 offers its potential applications for reusable studies. This work proposed the potential application of MAPbI3@g‐C3N4 towards H2 generation applications.

Summary Photocatalytic water splitting holds a key to realizing the hydrogen economy but faces a grand challenge, namely, the severe charge recombination causes low solar-to-hydrogen (STH) efficiency. This work reports a new form of MAPbI3 microcrystal (MAPbI3-MC)/monolayer MoS2 nanosheets (ML-MoS2) composite photocatalyst with type II heterojunction to effectively suppress the charge recombination for efficient photocatalytic hydrogen generation via HI splitting. The ML-MoS2/MAPbI3-MC is made of a large-sized MAPbI3-MC light harvester anchored with electrocatalytically active ML-MoS2 nanosheets to form a type II heterojunction that possesses a strong built-in electric field aligned between the spatially well-defined MAPbI3-MC and ML-MoS2 nanosheets to empower the photocatalyst with superior capability to effectively promote the charge separation. The ML-MoS2/MAPbI3-MC brings the hydrogen generation performance of the perovskite-based photocatalysts to a new horizon with a champion STH efficiency of 1.09% and a record hydrogen generation activity of 13.6 mmol g−1 h−1 under visible light.

… To explore the role of rGO in the photocatalytic H 2 evolution of MAPbI 3 /rGO, we measure the photoluminescence (PL) decay kinetics and PL spectra. The PL decay curves of Figure 4…

It was thought that the organic-inorganic hybrid perovskite MAPbI3 could be used to collect visible light for the photocatalytic hydrogen evolution reaction (HER). However, its ability to generate H2 is limited. Herein, we synthesized amorphous NiCoB through a redox method and coupled it with MAPbI3 to form the NiCoB/MAPbI3 composite photocatalyst by electrostatic self-assembly. 30% NiCoB/MAPbI3 exhibited the maximum H2 generation yield of 2625.57 μmol g-1 h-1, which was approximately 114 fold that of pristine MAPbI3 and much better than that of Pt/MAPbI3. In addition to the excellent photocatalytic HER capability, NiCoB/MAPbI3 maintained good stability in the 24 h cycling hydrogen evolution experiment. The photoelectric analysis showed that NiCoB as a cocatalyst could realize rapid charge separation. This work can offer a reference for the construction of efficient photocatalysts based on lead halide perovskites.

… perovskites ie MAPbI 3 have recently been emerging as promising photocatalysts for H 2 … charge recombination of MAPbI 3 at the nanoscale domain hinders its photocatalytic H 2 …

Three-dimensional (3D) and two-dimensional (2D) organic-inorganic hybrid perovskites (OIHPs) have demonstrated attractive potential for producing hydrogen fuel via photocatalytic pathway. However, the highly dynamic dissolution behaviour of 3D OIHPs in...

Powder samples of mixed halide perovskite MAPbBr3–xIx (MA = methylammonium ion, CH3NH3+) were prepared by employing a facile light-assisted halide-exchange method in aqueous halide solution at room temperature. It is found that the distribution of iodide ions in the MAPbBr3–xIx particles tends to be largest on the surface and becomes lower on going into the interior so that they have a correct bandgap funnel structure that is needed for transferring photogenerated charge carriers from the interior to the surface. Consequently, the MAPbBr3–xIx/Pt powder sample (250 mg) exhibits an enhanced photocatalytic activity for a H2 evolution under visible light (100 mW cm–2, λ ≥ 420 nm) with the rate of 651.2 μmol h–1 and a solar-to-chemical conversion efficiency of 1.05%.

The dramatic rise in carbon dioxide levels in the atmosphere caused by the continuous use of carbon fuels continues to have a significant impact on environmental degradation and the disappearance of energy reserves. Past few years have seen a significant increase in the interest in photocatalytic carbon dioxide reduction because of its ability to lower CO2 releases from the burning of fossil fuels while also producing fuels and important chemical products. Because of their excellent catalytic efficiency, great uniformity, lengthy charge diffusion layers and texture flexibility that enable accurate band gap and band line optimization, perovskite-based nanomaterials are perhaps the most advantageous among the numerous semiconductors proficient in accelerating CO2 conversion under visible light. Firstly, a brief insight into photocatalytic CO2 conversion mechanism and structural features of perovskites are discussed. Further the classification and selection of perovskites for Z and S-scheme heterojunctions and their role in photocatalytic CO2 reduction analysed. The efficient modification and engineering of heterojunctions via co-catalyst loading, morphology control and vacancy introduction have been comprehensively reviewed. Third, the state-of-the-art achievements of perovskite-based Z-scheme and S-scheme heterojunctions are systematically summarized and discussed. Finally, the challenges, bottlenecks and future perspectives are discussed to provide a pathway for applying perovskite-based heterojunctions for solar-to-chemical energy conversion.

Perovskite quantum dots (PQDs) hold immense potential as photocatalysts for CO2 reduction due to their remarkable quantum properties, which facilitates the generation of multiple excitons, providing the necessary high-energy electrons for CO2 photoreduction. However, harnessing multi-excitons in PQDs for superior photocatalysis remains challenging, as achieving the concurrent dissociation of excitons and interparticle energy transfer proves elusive. This study introduces a ligand density-controlled strategy to enhance both exciton dissociation and interparticle energy transfer in CsPbBr3 PQDs. Optimized CsPbBr3 PQDs with the regulated ligand density exhibit efficient photocatalytic conversion of CO2 to CO, achieving a 2.26-fold improvement over unoptimized counterparts while maintaining chemical integrity. Multiple analytical techniques, including Kelvin probe force microscopy, temperature-dependent photoluminescence, femtosecond transient absorption spectroscopy, and density functional theory calculations, collectively affirm that the proper ligand termination promotes the charge separation and the interparticle transfer through ligand-mediated interfacial electron coupling and electronic interactions. This work reveals ligand density-dependent variations in the gas-solid photocatalytic CO2 reduction performance of CsPbBr3 PQDs, underscoring the importance of ligand engineering for enhancing quantum dot photocatalysis.

Heterojunctions, known for their decent separation of photo‐generated electrons and holes, are promising for photocatalytic CO2 reduction. However, a significant obstacle in traditional post‐assembled heterojunctions is the high interfacial barrier for charge transfer caused by atomic lattice mismatch at multiphase interfaces. Here, as research prototypes, the study creates a lattice‐matched co‐atomic interface within CsPbBr3‐CsPb2Br5 polytypic nanocrystals (113‐125 PNs) through the proposed in situ hybrid strategy to elucidate the underlying charge transfer mechanism within this unique interface. Compared to CsPbBr3 nanocrystals, the 113–125 PNs exhibit a remarkable 3.6‐fold increase in photocatalytic CO2 reduction activity (173.3 µmol−1 g−1 within 5 h). Furthermore, Kelvin probe force microscopy results reveal an increase in the built‐in electric field within this lattice‐matched co‐atomic interface from 43.5 to 68.7 mV, providing a stronger driving force for charge separation and directional migration. Additionally, ultrafast transient absorption spectroscopy uncovers the additional charge carrier transfer pathways across this lattice‐matched co‐atomic interface. Thus, this unique co‐atomic interface significantly promotes the interfacial electronic coupling and mitigates the charge transfer barrier, thus facilitating efficient charge separation and transfer. These insights underscore the importance of interfacial structure in heterojunction design and comprehending the intricate interplay between interface and carrier dynamics.

… emissions and convert CO 2 into value-added chemicals. Metal halide perovskite (MHP) … for diverse photocatalytic applications, especially for CO 2 photoreduction. Due to their tunable …

Mimicking the natural photosynthesis process to convert carbon dioxide into value-added chemicals is vital to solving both the climate crisis worldwide and the depletion of fossil fuels. Herein, we explore the synthesis of 2D FAPbBr3 nanoplate combined with 2D Ti3C2 nanosheet to form a 2D/2D FAPbBr3/Ti3C2 Schottky heterojunction using facile hot-injection and in-situ growth approaches. The Schottky heterojunction of FAPbBr3/Ti3C2 over large interfacial contact provides abundant channels for transferring photogenerated carriers from FAPbBr3 nanoplate to Ti3C2 nanosheet. The experimental results showed a CO yield of 93.82 μmol·g-1·h-1 with ethyl acetate/deionization water as a sacrificial reagent for FAPbBr3/Ti3C2 composite, which was 1.25-fold enhancement that on pristine FAPbBr3 nanoplates. The large 2D heterointerface can efficiently accelerate the spatial separation and transfer of photogenerated carriers and result in the superior photocatalytic activity and favorable stability of FAPbBr3/Ti3C2 photocatalysts, which are proved by in-situ X-ray photoelectron spectroscopy, photoluminescence, transient absorption spectra, and Mott-Schottky measurement. Thus, this work unveils that 2D/2D Schottky heterostructures would significantly improve the reaction activities of halide perovskite-based photocatalysts.

Metal halide perovskite with a suitable energy band structure and excellent visible-light response is a prospective photocatalyst for CO2 reduction. However, the reported inorganic halide perovskites have undesirable catalytic performances due to phase-sensitive and severe charge carrier recombination. Herein, we anchor the FAPbBr3 quantum dots (QDs) on Ti3C2 nanosheets to form a FAPbBr3/Ti3C2 composite within a Schottky heterojunction for photocatalytic CO2 reduction. Upon visible-light illumination, the FAPbBr3/Ti3C2 composite photocatalyst exhibits an appealing photocatalytic performance in the presence of deionized water. The Ti3C2 nanosheet acts as an electron acceptor to promote the rapid separation of excitons and supply specific catalytic sites. An optimal electron consumption rate of 717.18 μmol/g·h is obtained by the FAPbBr3/0.2-Ti3C2 composite, which has a 2.08-fold improvement over the pristine FAPbBr3 QDs (343.90 μmol/g·h). Meanwhile, the FAPbBr3/Ti3C2 photocatalyst also displays a superior stability during photocatalytic reaction. This work expands a new insight and platform for designing superb perovskite/MXene-based photocatalysts for CO2 reduction.

Abstract With the target of bringing out a sustainable carbon–neutral system, halide perovskite materials have been explored to fulfil the requirements of solar-to-fuel conversion. Herein, formamidinium (CH(NH2)2+) lead bromide quantum dot (FAPbBr3 QD) as a novel of photocatalyst is researched, which exhibits an excellent photostability and the optimum CO yield rate of 181.25 μmol·g−1·h−1 towards photocatalytic CO2 reduction in the mixed solvent of deionized water/ethyl acetate. Furthermore, the kinetic features of exciton bleach and photoluminescence spectra infer that FAPbBr3 QDs have an enough lifetime to separate and transfer charges for adsorbing CO2 molecules, thus facilitating the photocatalytic CO2 reduction. This study puts forward a reliable avenue of organic–inorganic hybrid perovskite materials as efficient photocatalysts to convert CO2 into valuable chemical fuels.

… surface of FAPbBr 3 NCs (FAPbBr 3 /PbI … FAPbBr 3 /PbI 2 composite exhibits significantly improved stability and activity in comparison with pristine FAPbBr 3 NCs for photocatalytic CO 2 …

… in photocatalytic CO 2 reduction. Despite its excellent properties in material structure, a single perovskite still has its drawbacks, such as lack of active sites, low stability in catalysis, and …

Metal halide perovskites with direct bandgap and strong light absorption are promising materials for harvesting solar energy, however, their relatively narrow bandgap limits their redox ability when used as a photocatalyst. Adding a second semiconductor component with the appropriate band structure offsets can generate a Z-scheme photocatalytic system, taking full advantage of the perovskite's intrinsic properties. In this work, we develop a direct Z-scheme photocatalyst based on formamidinium lead bromide and bismuth tungstate (FAPbBr3/Bi2WO6) with strong redox ability, for artificial solar-to-chemical energy conversion. With desir-able band offsets and strong joint redox potential, the dual photocatalyst is shown to form a semi-coherent hetero-interface. Ultra-fast transient infrared absorption studies employing selective excitation reveal synergetic photocarrier dynamics and demonstrate Z-scheme charge transfer mechanisms. Under simulated solar irradiation, a large driving force photoredox reaction (ca. 2.57 eV) of CO2 reduction coupled with benzyl alcohol oxidation to benzaldehyde is achieved on the Z-scheme FAPbBr3/Bi2WO6 photocata-lyst, harnessing the full synergetic potential of the combined system.

The photocatalytic reduction of CO2 into valuable chemicals and fuels has become a significant research focus in recent years due to its environmental sustainability and energy efficiency. Metal halide perovskites (MHPs), renowned for their remarkable optoelectronic properties and tunable structures, are regarded as promising photocatalysts. Yet, their practical uses are constrained by inherent instability, severe electron-hole recombination, and a scarcity of active sites, prompting substantial research efforts to optimize MHP-based photocatalysts. This review summarizes the latest advancements in MHP-based photocatalysis. First the fundamental principles of photocatalysis are outlined and the structural and optical characteristics of MHPs are evaluated. Then key strategies for enhancing MHP photocatalysts, including morphology and surface modification, encapsulation, metal cation doping, heterojunction engineering, and molecular immobilization are highlighted. Finally, considering recent research progress and the needs for industrial application, challenges and future prospects are explored. This review aims to support researchers in the development of more efficient and stable MHP-based photocatalysts.

Halide perovskite (HP) semiconductors have attracted considerable attention due to their easy preparation methods and unique optoelectronic properties such as high absorption coefficients, tunable bandgap engineering, and long charge‐carrier diffusion lengths. While this class of materials has dominated the field of perovskite solar cells for the past two decades, there is now a shift toward other applications, particularly in solar energy harvesting and conversion as photocatalysts. This concept paper provides insights into the milestones of halide perovskite photocatalysts by highlighting their key properties that determine the catalytic functionality and performance. It briefly reviews the important physicochemical and structural properties of halide perovskites that influence their photocatalytic performances. Finally, it discusses the main challenges and strategies for enhancing their performance and durability.

Over the past few decades, organic–inorganic halide perovskites (OIHPs) as novel photocatalyst materials have attracted intensive attention for an impressive variety of photocatalytic applications due to their excellent photophysical (chemical) properties. Regarding practical application and future commercialization, the air–water stability and photocatalytic performance of OIHPs need to be further improved. Accordingly, studying modification strategies and interfacial interaction mechanisms is crucial. In this review, the current progress in the development and photocatalytic fundamentals of OIHPs is summarized. Furthermore, the structural modification strategies of OIHPs, including dimensionality control, heterojunction design, encapsulation techniques, and so on for the enhancement of charge‐carrier transfer and the enlargement of long‐term stability, are elucidated. Subsequently, the interfacial mechanisms and charge‐carrier dynamics of OIHPs during the photocatalytic process are systematically specified and classified via diverse photophysical and electrochemical characterization methods, such as time‐resolved photoluminescence measurements, ultrafast transient absorption spectroscopy, electrochemical impedance spectroscopy measurements, transient photocurrent densities, and so forth. Eventually, various photocatalytic applications of OIHPs, including hydrogen evolution, CO2 reduction, pollutant degradation, and photocatalytic conversion of organic matter.

… Here we report the development and application of the solar-driven photocatalyst FAPbBr3/Bi2WO6, for the large driving force photoredox reaction (ca. 2.57 eV) of CO2 reduction …

… products in different solvents using FAPbBr 3 photocatalysts. Reproduced with permission … e) Different solvents for photocatalytic CO 2 reduction and advisible types of light. Rate of …

The over-use of fossil fuels leads to a sharp increase in atmospheric concentrations of carbon dioxide (CO2), which seriously contributes to the energy crisis and climate problems. The direct transformation...

… photocatalytic hydrogen evolution reaction (HER) on CH 3 NH 3 PbI 3 surface. We find that both the lead (Pb) atoms and the surface organic molecules play essential roles, leading to a …

… reported 3D perovskite photocatalysts. This work is expected to provide insights into expanding metal halide perovskite-based photocatalysts for efficient photocatalytic H 2 evolution. …

Metal halide perovskites (MHPs) have emerged as attractive candidates for producing green hydrogen via photocatalytic pathway. However, the presence of abundant defects and absence of efficient hydrogen evolution reaction (HER) active sites on MHPs seriously limit the solar-to-chemical (STC) conversion efficiency. Herein, to address this issue, we present a bi-functionalization strategy through decorating MHPs with a molecular molybdenum-sulfur-containing co-catalyst precursor. By virtue of the strong chemical interaction between lead and sulfur and the good dispersion of the molecular co-catalyst precursor in the deposition solution, a uniform and intimate decoration of the MHPs surface with lead sulfide (PbS) and amorphous molybdenum sulfide (MoSx) co-catalysts is obtained simultaneously. We show that the PbS co-catalyst can effectively passivate the Pb-related defects on the MHPs surface, thus retarding the charge recombination and promoting the charge transfer efficiency significantly. The amorphous MoSx co-catalyst further promotes the extraction of photogenerated electrons from MHPs and facilitates the HER catalysis. Consequently, drastically enhanced photocatalytic HER activities are obtained on representative MHPs through the synergistic functionalization of PbS and MoSx co-catalysts. A solar-to-chemical (STC) conversion efficiency of ca. 4.63% is achieved on the bi-functionalized FAPbBr3-xIx, which is among the highest values reported for MHPs.

This work demonstrates that carbonized polymer dots (CPDs) can efficiently promote the charge separation and photocatalytic performance of metal halide perovskites, highlighting their excellent charge-transfer ability and great potential in developing efficient perovskite-based hybrid photocatalysts.