Coupling CsPbBr3 Quantum Dots with Covalent Triazine Frameworks for Visible-Light-Driven CO2 Reduction

PVP Passivated δ-CsPbI3: Vacancy Induced Visible-Light Absorption and Efficient Photocatalysis

The aqueous instability of halide perovskite seriously hinders its direct application in water as a potential photocatalyst. Here, we prepared a new type of polyvinylpyrrolidone (PVP) passivated δ-CsPbI3 (δ-CsPbI3@PVP) microcrystal by a facile method. This material can be uniformly dispersed in water and stably maintain its crystal structure for a long time, breaking through the bottleneck of halide perovskite photocatalysis in water. Under visible light, δ-CsPbI3@PVP can almost completely photodegrade organic dyes (including Rhodamine B, methylene blue, and crystal violet) in only 20 min. The efficient photocatalytic activity is attributed to the enhanced visible light absorption arising from PbI2 defects in δ-CsPbI3@PVP and the intrinsic low photoluminescence quantum yield of δ-CsPbI3, which induces efficient light absorption and photocatalytic activity. We highlight δ-CsPbI3@PVP as an effective aqueous photocatalyst, and this study provides new insights into how to exploit the potential of halide perovskite in photocatalytic applications.

A Three-in-One Integrated Cs3Bi2Br9@Co3O4 Heterostructure with Photoinduced Self-Heating Effect for Synergistically Enhancing the Photothermal CO2 Reduction

Photothermal catalysis, which applies solar energy to produce photogenerated e-/h+ pairs as well as provide heat input, is recognized as a promising technology for high conversion efficiency of CO2 to value-added solar fuels. In this work, a "shooting three birds with one stone" approach is demonstrated to significantly enhance the photothermal CO2 reduction over the Cs3Bi2Br9@Co3O4 (CBB@Co3O4) heterostructure. Initially, Co3O4 with photoinduced self-heating effect serves as a photothermal material to elevate the temperature of the photocatalyst, which kinetically accelerates the catalytic reaction. Meanwhile, a p-n heterojunction is constructed between the p-type Co3O4 and n-type Cs3Bi2Br9 semiconductors, which has an intrinsic built-in electric field (BEF) to facilitate the separation of photogenerated e-/h+ pairs. Furthermore, the mesoporous Co3O4 matrix can afford abundant active sites for promoting adsorption/activation of CO2 molecules. Benefiting from these synergistic effects, the as-developed CBB@Co3O4 heterostructure achieves an impressive CO2-to-CO conversion rate of 168.56 µmol g-1 h-1 with no extra heat input. This work provides an insightful guidance for the construction of effective photothermal catalysts for CO2 reduction with high solar-to-fuel conversion efficiency.

Contemporary advances in photocatalytic CO2 reduction using single-atom catalysts supported on carbon-based materials

The persistent issue of CO2 emissions and their subsequent impact on the Earth's atmosphere can be effectively addressed through the utilization of efficient photocatalysts. Employing a sustainable carbon cycle via photocatalysis presents a promising technology for simultaneously managing the greenhouse effect and the energy dilemma. However, the efficiency of energy conversion encounters limitations due to inadequate carrier utilization and a deficiency of reactive sites. Single-atom catalysts (SACs) have demonstrated exceptional performance in efficiently addressing the aforementioned challenges. This review article commences with an overview of SAC types, structures, fundamentals, synthesis strategies, and characterizations, providing a logical foundation for the design and properties of SACs based on the correlation between their structure and efficiency. Additionally, we delve into the general mechanism and the role of SACs in photocatalytic CO2 reduction. Furthermore, we furnish a comprehensive survey of the latest advancements in SACs concerning their capacity to enhance efficiency, long-term stability, and selectivity in CO2 reduction. Carbon-structured support materials such as covalent organic frameworks (COFs), graphitic carbon nitride (g-C3N4), metal-organic frameworks (MOFs), covalent triazine frameworks (CTFs), and graphene-based photocatalysts have garnered significant attention due to their substantial surface area, superior conductivity, and chemical stability. These carbon-based materials are frequently chosen as support matrices for anchoring single metal atoms, thereby enhancing catalytic activity and selectivity. The motivation behind this review article lies in evaluating recent developments in photocatalytic CO2 reduction employing SACs supported on carbon substrates. In conclusion, we highlight critical issues associated with SACs, potential prospects in photocatalytic CO2 reduction, and existing challenges. This review article is dedicated to providing a comprehensive and organized compilation of recent research findings on carbon support materials for SACs in photocatalytic CO2 reduction, with a specific focus on materials that are environmentally friendly, readily accessible, cost-effective, and exceptionally efficient. This work offers a critical assessment and serves as a systematic reference for the development of SACs supported on MOFs, COFs, g-C3N4, graphene, and CTFs support materials to enhance photocatalytic CO2 conversion.

Strategies for Enhancing the Photocatalytic and Electrocatalytic Efficiency of Covalent Triazine Frameworks for CO2 Reduction

Converting carbon dioxide (CO2 ) into fuel and high-value-added chemicals is considered a green and effective way to solve global energy and environmental problems. Covalent triazine frameworks (CTFs) are extensively utilized as an emerging catalyst for photo/electrocatalytic CO2 reduction reaction (CO2 RR) recently recognized for their distinctive qualities, including excellent thermal and chemical stability, π-conjugated structure, rich nitrogen content, and a strong affinity for CO2 , etc. Nevertheless, single-component CTFs have the problems of accelerated recombination of photoexcited electron-hole pairs and restricted conductivity, which limit their application for photo/electrocatalytic CO2 RR. Therefore, emphasis will then summarize the strategies for enhancing the photocatalytic and electrocatalytic efficiency of CTFs for CO2 RR in this paper, including atom doping, constructing a heterojunction structure, etc. This review first illustrates the synthesis strategies of CTFs and the advantages of CTFs in the field of photo/electrocatalytic CO2 RR. Subsequently, the mechanism of CTF-based materials in photo/electrocatalytic CO2 RR is described. Lastly, the challenges and future prospects of CTFs in photo/electrocatalytic CO2 RR are addressed, which offers a fresh perspective for the future development of CTFs in photo/electrocatalytic CO2 RR.

Synthesis of CsPbBr3 in Micro Total Reaction System: Fast Operation Space Mapping and Subsecond Growth Process Monitoring

Lead halide perovskite nanocrystals (LHP NCs) have the characteristics of fast reaction kinetics and crystal instability due to the intrinsically highly ionic bonding between the respective ions, which bring challenges for revealing the growth kinetics and practical applications. Compared with conventional batch synthesis methods, the single-function microreactor can achieve precise and stable control of the NCs synthesis process, but it still has the shortcoming of not being able to obtain information about the growth process. In this study, a micro Total Reaction System (μTRS) with remote control, online detection, and rapid data analysis functions is designed. μTRS can sample the photoluminescence information of CsPbBr3 NCs growth in ligand-assisted reprecipitation method. CsPbBr3 NCs with an emission range of 435-492 nm are successfully detected, which breaks the record of the smallest size of CsPbBr3 NCs synthesized directly from precursors. The real-time feature of μTRS enables the construction of an automated close-loop synthesis system. Besides, the rapid acquisition and timely processing of product information enable the rapid mapping of the operation space for CsPbBr3 NCs preparation, which provides a reliable and learnable data set for designing a fully autonomous microreaction system capable of synthesizing NCs.

Self-supported CsPbBr3/Ti3C2Tx MXene aerogels towards efficient photocatalytic CO2 reduction

Aerogels, especially MXene aerogels, are an ideal multifunctional platform for developing efficient photocatalysts for CO₂ reduction because they are featured by abundant catalytic sites, high electrical conductivity, high gas absorption ability and self-supported structure. However, the pristine MXene aerogel has almost no ability to utilize light, which requires additional photosensitizers to assist it in achieving efficient light harvesting. Herein, we immobilized colloidal CsPbBr₃ nanocrystals (NCs) onto the self-supported Ti₃C₂T_x (where T_x represents surface terminations such as fluorine, oxygen, and hydroxyl groups) MXene aerogels for photocatalytic CO₂ reduction. The resultant CsPbBr₃/Ti₃C₂T_x MXene aerogels exhibit a remarkable photocatalytic activity toward CO₂ reduction with total electron consumption rate of 112.6 μmol g^-1h^-1, which is 6.6-fold higher than that of the pristine CsPbBr₃ NC powders. The improvement of the photocatalytic performance is presumably attributed to the strong light absorption, effective charge separation and CO₂ adsorption in the CsPbBr₃/Ti₃C₂T_x MXene aerogels. This work presents an effective perovskite-based photocatalyst in aerogel form and opens a new avenue for their solar-to-fuel conversions.

In situgrowth strategy to construct perovskite quantum dot@covalent organic framework composites with enhanced water stability

Metal halide perovskite quantum dots (QDs) have excellent optoelectronic properties; however, their poor stability under water or thermal conditions remains an obstacle to commercialization. Here, we used a carboxyl functional group (-COOH) to enhance the ability of a covalent organic framework (COF) to adsorb lead ions and grow CH₃NH₃PbBr₃(MAPbBr₃) QDsin situinto a mesoporous carboxyl-functionalized COF to construct MAPbBr₃QDs@COF core-shell-like composites to improve the stability of perovskites. Owing to the protection of the COF, the as-prepared composites exhibited enhanced water stability, and the characteristic fluorescence was maintained for more than 15 d. These MAPbBr₃QDs@COF composites can be used to fabricate white light-emitting diodes with a color comparable to natural white emission. This work demonstrates the importance of functional groups for thein situgrowth of perovskite QDs, and coating with a porous structure is an effective way to improve the stability of metal halide perovskites.

Stabilization and Performance Enhancement Strategies for Halide Perovskite Photocatalysts

Solar-energy-powered photocatalytic fuel production and chemical synthesis are widely recognized as viable technological solutions for a sustainable energy future. However, the requirement of high-performance photocatalysts is a major bottleneck. Halide perovskites, a category of diversified semiconductor materials with suitable energy-band-enabled high-light-utilization efficiencies, exceptionally long charge-carrier-diffusion-length-facilitated charge transport, and readily tailorable compositional, structural, and morphological properties, have emerged as a new class of photocatalysts for efficient hydrogen evolution, CO₂ reduction, and various organic synthesis reactions. Despite the noticeable progress, the development of high-performance halide perovskite photocatalysts (HPPs) is still hindered by several key challenges: the strong ionic nature and high hydrolysis tendency induce instability and an unsatisfactory activity due to the need for a coactive component to realize redox processes. Herein, the recently developed advanced strategies to enhance the stability and photocatalytic activity of HPPs are comprehensively reviewed. The widely applicable stability enhancement strategies are first articulated, and the activity improvement strategies for fuel production and chemical synthesis are then explored. Finally, the challenges and future perspectives associated with the application of HPPs in efficient production of fuels and value-added chemicals are presented, indicating the irreplaceable role of the HPPs in the field of photocatalysis.

Ultralong Lifetime of Plasmon-Excited Electrons Realized in Nonepitaxial/Epitaxial Au@CdS/CsPbBr3 Triple-Heteronanocrystals

Combination of the strong light-absorbing power of plasmonic metals with the superior charge carrier dynamics of halide perovskites is appealing for bio-inspired solar-energy conversion due to the potential to acquire long-lived plasmon-induced hot electrons. However, the direct coupling of these two materials, with Au/CsPbBr₃ heteronanocrystals (HNCs) as a prototype, results in severe suppression of plasmon resonances. The present work shows that interfacial engineering is a key knob for overcoming this impediment, based on the creation of a CdS mediate layer between Au and CsPbBr₃ forming atomically organized Au-CdS and CdS-CsPbBr₃ interfaces by nonepitaxial/epitaxial combined strategy. Transient spectroscopy studies demonstrate that the resulting Au@CdS/CsPbBr₃ HNCs generate remarkably long-lived plasmon-induced charge carriers with lifetime up to nanosecond timescale, which is several orders of magnitude longer than those reported for colloidal plasmonic metal-semiconductor systems. Such long-lived carriers extracted from plasmonic antennas enable to drive CO₂ photoreduction with efficiency outperforming previously reported CsPbBr₃ -based photocatalysts. The findings disclose a new paradigm for achieving much elongated time windows to harness the substantial energy of transient plasmons through realization of synergistic coupling of plasmonic metals and halide perovskites.

Optimizing the Synthetic Conditions of "Green" Colloidal AgBiS2 Nanocrystals Using a Low-Cost Sulfur Source

Colloidal AgBiS₂ nanocrystals (NCs) have attracted increasing attention as a near-infrared absorbent materials with non-toxic elements and a high absorption coefficient. In recent years, colloidal AgBiS₂ NCs have typically been synthesized via the hot injection method using hexamethyldisilathiane (TMS) as the sulfur source. However, the cost of TMS is one of the biggest obstacles to large-scale synthesis of colloidal AgBiS₂ NCs. Herein, we synthesized colloidal AgBiS₂ NCs using oleylamine@sulfur (OLA-S) solution as the sulfur source instead of TMS and optimized the synthesis conditions of colloidal AgBiS₂ NCs. By controlling the reaction injection temperature and the dosage of OLA-S, colloidal AgBiS₂ NCs with adjustable size can be synthesized. Compared with TMS-based colloidal AgBiS₂ NCs, the colloidal AgBiS₂ NCs based on OLA-S has good crystallinity and fewer defects.

2D/2D Inorganic/Organic Hybrid of Lead-Free Cs2AgBiBr6 Double Perovskite/Covalent Triazine Frameworks with Boosted Charge Separation and Efficient CO2 Photoreduction

Heterojunction construction, especially the inorganic/organic hybrids, is regarded as a universal and effective strategy to achieve high-performance photocatalysts. Herein, a 2D/2D inorganic/organic hybrid photocatalyst was constructed by the electrostatic self-assembly of the lead-free double-perovskite of Cs₂AgBiBr₆ nanosheets (NSs) and covalent triazine framework (CTF) NSs. The resultant Cs₂AgBiBr₆/CTF-1 (CABB/CTF-1) hybrid possessed a large surface-to-surface contact area, ensuring intimate interfacial interaction and efficient charge transfer/separation. Meanwhile, the periodical pore structure of CTF-1 endowed the CABB/CTF-1 hybrid with enhanced CO₂ adsorption/activation capacity. Consequently, the 2D/2D CABB/CTF-1 hybrid exhibited a remarkable photocatalytic performance toward CO₂ reduction. Based on the band structure analysis and various characterization techniques, for example, X-ray photoelectron spectra and electron spin resonance, an S-scheme charge transfer mechanism was proposed. This study presents a new protocol for designing 2D/2D inorganic/organic hybrid photocatalytic systems, which hold great potentials in solar fuel applications.

An Artificial Photosystem of Metal-Insulator-CTF Nanoarchitectures for Highly Efficient and Selective CO2 Conversion to CO

It is of pivotal significance to explore robust photocatalysts to promote the photoreduction of CO₂ into solar fuels. Herein, an intelligent metal-insulator-semiconductor (MIS) nano-architectural photosystem was constructed by electrostatic self-assembly between cetyltrimethylammonium bromide (CTAB) insulator-capped metal Ni nanoparticles (NPs) and covalent triazine-based frameworks (CTF-1). The metal-insulator-CTF composites unveiled a substantially higher CO evolution rate (1254.15 μmol g^-1  h^-1 ) compared with primitive CTF-1 (1.08 μmol g^-1  h^-1 ) and reached considerable selectivity (98.9 %) under visible-light irradiation. The superior photocatalytic CO₂ conversion activity over Ni-CTAB-CTF nanoarchitecture could be attributed to the larger surface area, reinforced visible-light response, and CO₂ capture capacity. More importantly, the Ni-CTAB-CTF nanoarchitecture endowed the photoexcited electrons on CTF-1 with the ability to tunnel across the thin CTAB insulating layer, directionally migrating to Ni NPs and thereby leading to the efficient separation of photogenerated electrons and holes in the photosystem. In addition, isotope-labeled (¹³ CO₂ ) tracer results verified that the reduction products come from CO₂ rather than the decomposition of the photocatalysts. This study opens a new avenue for establishing a highly efficient and selective artificial photosystem for CO₂ conversion.

2D/2D CsPbBr3/BiOCl Heterojunction with an S-Scheme Charge Transfer for Boosting the Photocatalytic Conversion of CO2

The rational design of a two-dimensional (2D)/2D "face-to-face" heterojunction photocatalyst is crucial for the mediation of interfacial charge transfer/separation. Herein, a unique 2D/2D step-scheme (S-scheme) photocatalyst of CsPbBr₃/BiOCl is constructed by the self-assembly of CsPbBr₃ and BiOCl nanosheets (NSs). Profiting from the effective interface contact and appropriate band structures between CsPbBr₃ and BiOCl NSs, a valid S-scheme heterojunction of CsPbBr₃/BiOCl is established. Density functional theory (DFT) calculations and a series of characterization techniques including X-ray photoelectron spectra (XPS), photoassisted Kelvin probe force microscopy (KPFM), and electron spin resonance (ESR) systematically corroborate the S-scheme charge-transfer mechanism between CsPbBr₃ and BiOCl. The formation of an S-scheme heterojunction endows the photocatalyst with boosted charge separation and retainment of the highest redox ability. As a result, the obtained 2D/2D CsPbBr₃/BiOCl S-scheme photocatalyst shows much superior CO₂-reduction performance to single CsPbBr₃ and BiOCl. This investigation provides new insights into the construction of novel S-scheme heterojunctions based on 2D/2D photocatalytic systems.

Electrocatalysis CO2 to Tunable Syngas upon Fe Clusters Catalyst Dispersed on Bamboo-like NCTs

Herein, we report a catalyst of Fe@NBCT with a high performance in electrocatalytic CO₂ to syngas with tunable H₂/CO ratio. Both in situ synchrotron radiation Fourier transform infrared spectra (SR-FTIR) and density functional theory (DFT) calculation proved that the differing N-doping carbon matrix and Fe nanoclusters (NCs) play dramatic roles in tuning the ratio of syngas during the electrocatalytic carbon dioxide reduction reaction (EC-CO₂RR) process.

Large-Scale Production of Ligand-Engineered Robust Lead Halide Perovskite Nanocrystals by a Droplet-Based Microreactor System

Cesium lead halide perovskite nanocrystals (CLHP NCs) have a wide range of potential applications benefited from the properties of high photoluminescence quantum yield (PLQY), wide luminous gamut, and narrow half peak width. However, due to the ionic nature and sensitivity to moisture, oxygen, or heat, perovskite nanocrystals are too fragile to maintain their crystal structure and optical properties. This work proposes solutions to two key issues in the development of CLHP NCs. First, a productive droplet-based microreactor system is designed to accomplish the scale-up production of CLHP NCs, obtaining sub-gram high-purity nanocrystal powders in a single production process. Second, CLHP NCs which are stable in polar solvents, air environment, and high temperature by using 3-aminopropyl triethoxysilane (APTES) as basic ligand are obtained. Wrapped with Si-O-Si generated by APTES, the CLHP NCs exhibit a longer fluorescence lifetime and higher quantum yield. Especially, the PLQY of CsPbBr₃ @APTES can be stable at higher than 90% for more than 10 days. The Si-O-Si protective layer can also suppress the anion exchange between CsPbBr₃ and CsPbI₃ , maintaining the monochromaticity of nanocrystal luminescence. Eventually, full-spectrum quantum light-emitting diode (QLED) beads with robust nanocrystals are fabricated. The gamut of CsPbX₃ @APTES encompasses 140% of the NTSC color gamut standard.

COF-5/CoAl-LDH Nanocomposite Heterojunction for Enhanced Visible-Light-Driven CO2 Reduction

Photocatalytic conversion of CO₂ into value-added chemical fuels is an attractive route to mitigate global warming and the energy crisis. Reasonable design of optical properties and electronic behavior of the photocatalyst are essential to improve their catalytic activity. Herein, the 1D/2D heterojunction by direct in-situ synthesis of the covalent organic framework (COF)-5 colloid on the surface of CoAl layered double hydroxide (LDH) was used as the prospective photocatalyst for CO₂ reduction. COF-5/CoAl-LDH nanocomposite achieved 265.4 μmol g^-1 of CO with 94.6 % selectivity over CH₄ evolution in 5 h under visible light irradiation, which was 4.8 and 2.3 times higher than those of COF-5 colloid and CoAl-LDH, respectively. The enhanced catalytic activity was derived from the increased visible-light activity and the construction of type II-2 heterojunction, which greatly optimized visible light harvesting and accelerated the efficient separation of the photoinduced holes and electrons. This work paves the way for rational design of heterojunction catalysts in photocatalytic CO₂ reduction.

Graphitic Aza-Fused π-Conjugated Networks: Construction, Engineering, and Task-Specific Applications

2D π-conjugated networks linked by aza-fused units represent a pivotal category of graphitic materials with stacked nanosheet architectures. Extensive efforts have been directed at their fabrication and application since the discovery of covalent triazine frameworks (CTFs). Besides the triazine cores, tricycloquinazoline and hexaazatriphenylene linkages are further introduced to tailor the structures and properties. Diverse related materials have been developed rapidly, and a thorough outlook is necessitated to unveil the structure-property-application relationships across multiple subcategories, which is pivotal to guide the design and fabrication toward enhanced task-specific performance. Herein, the structure types and development of related materials including CTFs, covalent quinazoline networks, and hexaazatriphenylene networks, are introduced. Advanced synthetic strategies coupled with characterization techniques provide powerful tools to engineer the properties and tune the associated behaviors in corresponding applications. Case studies in the areas of gas adsorption, membrane-based separation, thermo-/electro-/photocatalysis, and energy storage are then addressed, focusing on the correlation between structure/property engineering and optimization of the corresponding performance, particularly the preferred features and strategies in each specific field. In the last section, the underlying challenges and opportunities in construction and application of this emerging and promising material category are discussed.

ZnSe Nanorods-CsSnCl3 Perovskite Heterojunction Composite for Photocatalytic CO2 Reduction

Utilizing sunlight to convert CO₂ into chemical fuels could simultaneously address the greenhouse effect and fossil fuel crisis. ZnSe nanocrystals are promising candidates for photocatalysis because of their low toxicity and excellent photoelectric properties. However, pristine ZnSe generally has low catalytic activities due to serious charge recombination and the lack of efficient catalytic sites for CO₂ reduction. Herein, a ZnSe nanorods-CsSnCl₃ perovskite (ZnSe-CsSnCl₃) type II heterojunction composite is designed and prepared for photocatalytic CO₂ reduction. The ZnSe-CsSnCl₃ type II heterojunction composite exhibits enhanced photocatalytic activity for CO₂ reduction with respect to pristine ZnSe nanorods. The experimental characterizations and theoretical calculations reveal that the efficient charge separation and lowered free energy of CO₂ reduction facilitate the CO₂ conversion on the ZnSe-CsSnCl₃ heterojunction composite. This work presents a type II heterojunction composite photocatalyst based on ecofriendly metal chalcogenides and metal halide perovskites. Our study has also promoted the understanding of the CO₂ reduction mechanisms on perovskite nanocrystals, which could be valuable for the development of metal halide perovskite photocatalysts.

In-Situ Generated CsPbBr3 Nanocrystals on O-Defective WO3 for Photocatalytic CO2 Reduction

Metal halide perovskite (MHP) nanocrystals (NCs) have shown promising application in photocatalytic CO₂ reduction, but their activities are still largely restrained by severe charge recombination and narrow solar spectrum response. Assembly of heterojunctions can be beneficial to the charge separation in MHPs while the assembly process usually brings native interfacial defects, impeding efficient charge separation between two materials. Herein, an in-situ generation strategy was developed to prepare CsPbBr₃ /WO₃ heterojunction, using WO₃ nanosheets (NSs) as growing substrate for the growth of CsPbBr₃ NCs. The developed CsPbBr₃ /WO₃ heterojunction exhibited a high-quality interface, greatly facilitating charge transfer between two semiconductors. The hybrid photocatalyst displayed an excellent activity toward CO₂ reduction, which was about 7-fold higher than pristine CsPbBr₃ NCs and 3.5-fold higher than their assembled counterparts. The experimental results and theoretical simulations revealed that a Z-scheme mechanism with a favorable internal electric field was responsible for the good performance of CsPbBr₃ /WO₃ heterojunction. By using O-defective WO₃ NSs as a near-infrared (NIR) light absorber, the CsPbBr₃ /WO₃ heterojunction could harvest NIR light and showed an impressive activity toward CO₂ reduction. This work demonstrates a new strategy to design MHP-based heterojunctions by synergistically considering the interface quality, charge transfer mode, interfacial electric field, and light response range between two semiconductors.

Step-Scheme Photocatalyst of CsPbBr3 Quantum Dots/BiOBr Nanosheets for Efficient CO2 Photoreduction

Heterojunction manipulation has been deemed as a promising approach in exploring efficient photocatalysts for CO₂ reduction. In this article, a novel step-scheme (S-scheme) photocatalyst of CsPbBr₃ quantum dots/BiOBr nanosheets (CPB/BiOBr) was fabricated via a facile self-assembly process. The strong interaction, staggered energy band alignments, and much different Fermi levels between CsPbBr₃ and BiOBr promised the formation of an S-scheme heterojunction. The resultant CPB/BiOBr heterojunction delivered remarkable photocatalytic performance in CO₂ reduction, with an electron consumption rate of 72.3 μmol g^-1 h^-1, which was 4.1 and 5.7 times that of single CsPbBr₃ and BiOBr, respectively. The superior photocatalytic performance originated from the impactful spatial separation of photoinduced electron-hole pairs, as well as the preservation of strongly reductive electrons for CO₂ reduction. This work offers a rational strategy to design S-scheme heterojunctions based on lead halide perovskites, which are expected to have potential applications in the field of photocatalysis and solar energy utilization.

Artificial Photosynthesis over Metal Halide Perovskites: Achievements, Challenges, and Prospects

Over the last 5 years, metal halide perovskites (MHPs) have emerged as promising photocatalysts for CO₂ reduction because of their extraodinary visible-light-harvesting capabilities and appropriate band structure. However, the CO₂ photoreduction activity of pristine MHPs is still unsatisfactory because of the phase instability, serious radiative recombination, and insufficient surface-active sites. This Perspective summarizes the strategies employed in recent studies for enhancing the photocatalytic CO₂ reduction performance of MHPs from the standpoint of structure engineering, which includes composition/dimension regulation, surface modification, and heterostructure construction. The relationship between the structure (composition, dimension, and shape) and photocatalytic performance is established, which is instructive for exploiting highly efficient perovskite-based photocatalysts in artificial photosynthesis applications. Further, some important challenges and future prospects of MHPs in this field are proposed and discussed.

Metal halide perovskites as an emergent catalyst for CO2 photoreduction: a minireview

The present minireview summarizes recent advances in the application of metal halide perovskite for CO₂ photoreduction.