Synthesis of Bi x O y I z from molecular precursor and selective photoreduction of CO 2 into CO

Recent advances on bismuth oxyhalides for photocatalytic CO2 reduction

Photocatalytic conversion of CO2 into fuels such as CO, CH4, and CH3OH, is a promising approach for achieving carbon neutrality. Bismuth oxyhalides (BiOX, where X = Cl, Br, and I) are appropriate photocatalysts for this purpose due to the merits of visible-light-active, efficient charge separation, and easy-to-modify crystal structure and surface properties. For practical applications, multiple strategies have been proposed to develop high-efficiency BiOX-based photocatalysts. This review summarizes the development of different approaches to prepare BiOX-based photocatalysts for efficient CO2 reduction. In the review, the fundamentals of photocatalytic CO2 reduction are introduced. Then, several widely used modification methods for BiOX photocatalysts are systematacially discussed, including heterojunction construction, introducing oxygen vacancies (OVs), Bi-enrichment, heteroatom-doping, and morphology design. Finally, the challenges and prospects in the design of future BiOX-based photocatalysis for efficient CO2 reduction are examined.

Research progress on photocatalytic reduction of CO2 based on ferroelectric materials

Transforming CO2 into renewable fuels or valuable carbon compounds could be a practical means to tackle the issues of global warming and energy crisis. Photocatalytic CO2 reduction is more energy-efficient and environmentally friendly, and offers a broader range of potential applications than other CO2 conversion techniques. Ferroelectric materials, which belong to a class of materials with switchable polarization, are attractive candidates as catalysts due to their distinctive and substantial impact on surface physical and chemical characteristics. This review provides a concise overview of the fundamental principles underlying photocatalysis and the mechanism involved in CO2 reduction. Additionally, the composition and properties of ferroelectric materials are introduced. This review expands on the research progress in using ferroelectric materials for photocatalytic reduction of CO2 from three perspectives: directly as a catalyst, by modification, and construction of heterojunctions. Finally, the future potential of ferroelectric materials for photocatalytic CO2 reduction is presented. This review may be a valuable guide for creating reasonable and more effective photocatalysts based on ferroelectric materials.

Construction of S-Scheme CuS/Bi5O7I Heterojunction for Boosted Photocatalytic Disinfection with Visible Light Exposure

In this paper, a novel S-scheme CuS/Bi5O7I heterojunction was successfully constructed using a two-step approach comprising the alkaline hydrothermal method and the adsorption–deposition method, and it consisted of Bi5O7I microrods with CuS particles covering the surface. The photocatalytic antibacterial effects on Escherichia coli (E. coli) were systematically examined with visible light exposure. The results suggested that the 3%-CuS/Bi5O7I composite showed the optimal antibacterial activity, completely inactivating E. coli (5 × 108 cfu/mL) in 180 min of irradiation. Moreover, the bacterial inactivation process was scientifically described. •O2− and h+ were the major active species for the inactivation of the bacteria. In the early stages, SOD and CAT initiated the protection system to avoid the oxidative destruction of the active species. Unfortunately, the antioxidant protection system was overwhelmed thereafter, which led to the destruction of the cell membrane, as evidenced by the microstructure changes in E. coli cells. Subsequently, the leakage of intracellular components including K+, proteins, and DNA resulted in the unavoidable death of E. coli. Due to the construction of the S-scheme heterojunction, the CuS/Bi5O7I composite displayed the boosted visible light harvesting, the high-efficiency separation of photogenerated electrons and holes, and a great redox capacity, contributing to an outstanding photocatalytic disinfection performance. This work offers a new opportunity for S-scheme Bi5O7I-based heterojunctions with potential application in water disinfection.

Potential utility of BiOX photocatalysts and their design/modification strategies for the optimum reduction of CO2

As an effective means to efficiently control the emissions of carbon dioxide (CO₂), photo-conversion of CO₂ into solar fuels (or their precursors) is meaningful both as an option to generate cleaner energy and to alleviate global warming. In this regard, bismuth oxyhalide (BiOX, where X = Cl, Br, and I) semiconductors have sparked considerable interest due to their multiple merits (e.g., visible light-harvesting, efficient charge carriers separation, and excellent chemical stability). In this review, the fundamental aspects of BiOX-based photocatalysts are discussed in relation to their modification strategies and associated reduction mechanisms of CO₂ to help expand their applicabilities. In this context, their performance is also evaluated in terms of the key performance metrics (e.g., quantum efficiency (QE), space-time yield (STY), and figure of merit (FoM)). Accordingly, the morphology design of BiOX materials is turned out as one of the most efficient strategies for the maximum yield of CO while the introduction of heterojunctions into BiOX materials was more suitable for CH₄ formation. As such, the adoption of the proper modification approach is recommended for efficient conversion of CO₂.

High-Throughput Strategies for the Design, Discovery, and Analysis of Bismuth-Based Photocatalysts

Bismuth-based nanostructures (BBNs) have attracted extensive research attention due to their tremendous development in the fields of photocatalysis and electro-catalysis. BBNs are considered potential photocatalysts because of their easily tuned electronic properties by changing their chemical composition, surface morphology, crystal structure, and band energies. However, their photocatalytic performance is not satisfactory yet, which limits their use in practical applications. To date, the charge carrier behavior of surface-engineered bismuth-based nanostructured photocatalysts has been under study to harness abundant solar energy for pollutant degradation and water splitting. Therefore, in this review, photocatalytic concepts and surface engineering for improving charge transport and the separation of available photocatalysts are first introduced. Afterward, the different strategies mainly implemented for the improvement of the photocatalytic activity are considered, including different synthetic approaches, the engineering of nanostructures, the influence of phase structure, and the active species produced from heterojunctions. Photocatalytic enhancement via the surface plasmon resonance effect is also examined and the photocatalytic performance of the bismuth-based photocatalytic mechanism is elucidated and discussed in detail, considering the different semiconductor junctions. Based on recent reports, current challenges and future directions for designing and developing bismuth-based nanostructured photocatalysts for enhanced photoactivity and stability are summarized.

The selective production of CH4via photocatalytic CO2 reduction over Pd-modified BiOCl

The selective production of CH4via photocatalytic CO2 reduction was achieved over Pd-modified BiOCl.

A review on bismuth oxyhalide based materials for photocatalysis

Photocatalytic solar energy transformation is the most encouraging solution to alleviate the environmental crisis and energy scarcity. Bismuth oxyhalide (BiOX) is an emerging class of materials that exhibits photocatalytic properties, such as resilient response to light, which causes enhanced energy conversion (solar energy) owing to their exceptional layered structure and attractive band structure. The present review presents a summary of results from the recent developments on the tuning and design of BiOX-based materials to improve the energy conversion. In particular, the preparation and tuning approaches that have the potential to enhance the photocatalytic behavior of BiOX and some other techniques, such as elemental doping, are addressed, which prevent the rapid recombination of charges, and formation of oxygen vacancies, facilitating an improvement in the photocatalytic reaction. Various frameworks are also presented, displaying the significance of BiOX-based nanocomposites. Finally, the main challenges and opportunities associated with the future progress of BiOX-based materials are presented. This review will provide an extended understanding and offer a preferred direction for the innovative design of BiOX-based materials for environmental and especially energy-based applications.

Advanced Two-Dimensional Heterojunction Photocatalysts of Stoichiometric and Non-Stoichiometric Bismuth Oxyhalides with Graphitic Carbon Nitride for Sustainable Energy and Environmental Applications

Semiconductor-based photocatalysis has been identified as an encouraging approach for solving the two main challenging problems, viz., remedying our polluted environment and the generation of sustainable chemical energy. Stoichiometric and non-stoichiometric bismuth oxyhalides (BiOX and BixOyXz where X = Cl, Br, and I) are a relatively new class of semiconductors that have attracted considerable interest for photocatalysis applications due to attributes, viz., high stability, suitable band structure, modifiable energy bandgap and two-dimensional layered structure capable of generating an internal electric field. Recently, the construction of heterojunction photocatalysts, especially 2D/2D systems, has convincingly drawn momentous attention practicably owing to the productive influence of having two dissimilar layered semiconductors in face-to-face contact with each other. This review has systematically summarized the recent progress on the 2D/2D heterojunction constructed between BiOX/BixOyXz with graphitic carbon nitride (g-C3N4). The band structure of individual components, various fabrication methods, different strategies developed for improving the photocatalytic performance and their applications in the degradation of various organic contaminants, hydrogen (H2) evolution, carbon dioxide (CO2) reduction, nitrogen (N2) fixation and the organic synthesis of clean chemicals are summarized. The perspectives and plausible opportunities for developing high performance BiOX/BixOyXz-g-C3N4 heterojunction photocatalysts are also discussed.

Facet effect of Bi5O7I nanocrystals on selective oxidation of benzylamine under visible light

Boosting photocatalytic activity in benzylamine oxidation was found for Bi5O7I with a (010) facet through facet engineering.

Powering the next industrial revolution: transitioning from nonrenewable energy to solar fuels via CO2 reduction

Solar energy has been used for decades for the direct production of electricity in various industries and devices; however, harnessing and storing this energy in the form of chemical bonds has emerged as a promising alternative to fossil fuel combustion. The common feedstocks for producing such solar fuels are carbon dioxide and water, yet only the photoconversion of carbon dioxide presents the opportunity to generate liquid fuels capable of integrating into our existing infrastructure, while simultaneously removing atmospheric greenhouse gas pollution. This review presents recent advances in photochemical solar fuel production technology. Although efforts in this field have created an incredible number of methods to convert carbon dioxide into gaseous and liquid fuels, these can generally be classified under one of four categories based on how incident sunlight is utilised: solar concentration for thermoconversion (Category 1), transformation toward electroconversion (Category 2), natural photosynthesis for bioconversion (Category 3), and artificial photosynthesis for direct photoconversion (Category 4). Select examples of developments within each of these categories is presented, showing the state-of-the-art in the use of carbon dioxide as a suitable feedstock for solar fuel production.

Solar energy has been used for decades for the direct production of electricity in various industries and devices. However, harnessing and storing this energy in the form of chemical bonds has emerged as a promising alternative to fossil fuels.

Bismuth-rich bismuth oxyiodide microspheres with abundant oxygen vacancies as an efficient photocatalyst for nitrogen fixation

A combined bismuth-rich and defect introduction strategy was used to prepare the H-Bi₅O₇I with abundant oxygen vacancies, which can effectively yield ammonia under visible light without any organic scavengers or noble-metal cocatalysts.

Bismuth-Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

Photocatalytic CO₂ conversion into solar fuels is an effective means for simultaneously solving both the greenhouse effect and energy crisis. In the past ten years, bismuth-based photocatalysts for environmental remediation have experienced a golden period of development. However, solar photocatalytic CO₂ conversion has only been developed over the past five years and, until now, no reviews have been published on bismuth-based photocatalysts for the photocatalytic conversion of CO₂ . For the first time, solar photocatalytic CO₂ conversion systems are reviewed herein. Synthetic methods and photocatalytic CO₂ performances of bismuth-based photocatalysts, including Sillén-structured BiOX (X=Cl, Br, I); Aurivillius-structured Bi₂ MO₆ (M=Mo, W); and Scheelite-structured BiVO₄ , Bi₂ S₃ , BiYO₃ , and BiOIO₃ , are summarized. In addition, activity-enhancing strategies for this photocatalyst family, including oxygen vacancies, bismuth-rich strategy, facet control, conventional type II heterojunction, Z-scheme heterojunction, and cocatalyst deposition, are reviewed. Finally, the main mechanistic research methods, such as in situ FTIR spectroscopy and theoretical calculations, are presented. Challenges and research trends reported in studies of bismuth-based photocatalysts for photocatalytic CO₂ conversion are discussed and summarized.

Ultrathin Nanotubes of Bi5O7I with a Reduced Band Gap as a High-Performance Photocatalyst

Bismuth oxyhalide (Bi-O-X) is a group of layered semiconductors, which are promising candidates for photocatalysis due to their inherent internal electric field and adjustable band gap through composition and morphology control. Bismuth-rich Bi-O-X has improved stability and advantageous band structure compared to those of Bi-O-X and hence has attracted an increasing amount of research interest. In this work, ultrathin nanotubes of Bi₅O₇I with a 5 nm diameter and a 1 nm wall are obtained through a hydrothermal method while the phase and morphology of the products are regulated by the pH values and polyvinylpyrrolidone (PVP) concentration of the reaction system, of which the products can be tuned from BiOI nanosheets to Bi₅O₇I nanobelts and ultrathin Bi₅O₇I nanotubes. PVP and pH control is important to the formation of the nanotubes as formation occurs via a PVP-guided oriented attachment from primary nanoparticles of Bi₅O₇I. The poorly crystalline and porous structure of the resultant bismuth-rich ultrathin nanotubes not only exposes more surface atoms but also exhibits a highly reduced conduction band minimum. The resultant band gap of 2.39 eV (as compared to 3.20 eV for the nanobelts) arises from the undercoordinated bismuth centers brought about by the rich oxygen vacancies in the nanotubes. The largely reduced band gap effectively enhances visible-light absorption, while the short charge-diffusion length of the nanotubes further reduces the charge-carrier loss in recombination.

Oxygen Vacancy Engineering of Bi24 O31 Cl10 for Boosted Photocatalytic CO2 Conversion

Unearthing an ideal model to describe the role of defect sites for boosting photocatalytic CO₂ reduction is rational and necessary, but it still remains a significant challenge. Herein, oxygen vacancies are introduced on the surface of Bi₂₄ O₃₁ Cl₁₀ photocatalyst (Bi₂₄ O₃₁ Cl₁₀ -OV) for fine-tuning the photocatalytic efficiency. The formation of oxygen vacancies leads to a new donor level near the conduction band minimum, which enables a faster charge transfer and higher carrier density. Moreover, oxygen vacancies can considerably reduce the energy for the formation of COOH* intermediates during CO₂ conversion. As a result, the activity of Bi₂₄ O₃₁ Cl₁₀ -OV for selective photoreduction of CO₂ to CO is significantly improved, with a CO generation rate of 0.9 μmol h^-1  g^-1 , which is nearly 4 times higher than that of pristine Bi₂₄ O₃₁ Cl₁₀ . This study reinforces our understanding of defect engineering in Bi-based photocatalysts and underscores the potential importance of implanting oxygen vacancies as an effective strategy for solar energy conversion.

Surface-Halogenation-Induced Atomic-Site Activation and Local Charge Separation for Superb CO2 Photoreduction

Solar-energy-driven CO₂ conversion into value-added chemical fuels holds great potential in renewable energy generation. However, the rapid recombination of charge carriers and deficient reactive sites, as two major obstacles, severely hampers the photocatalytic CO₂ reduction activity. Herein, a desirable surface halogenation strategy to address the aforementioned concerns over a Sillén-related layer-structured photocatalyst Bi₂ O₂ (OH)(NO₃ ) (BON) is demonstrated. The surface halogen ions that are anchored on the Bi atoms by replacing surface hydroxyls on the one hand facilitate the local charge separation, and, on the other hand, activate the hydroxyls that profoundly boost the adsorption of CO₂ molecules and protons and facilitate the CO₂ conversion process, as evidenced by experimental and theoretical results collectively. Among the three series of BON-X (X = Cl, Br, and I) catalysts, BON-Br shows the most substantially enhanced CO production rate (8.12 µmol g^-1 h^-1 ) without any sacrificial agents or cocatalysts, ≈73 times higher than that of pristine Bi₂ O₂ (OH)(NO₃ ), also exceeding that of the state-of-the-art photocatalysts reported to date. This work presents a surface polarization protocol for engineering charge behavior and reactive sites to promote photocatalysis, which shows great promise to the future design of high-performance materials for clean energy production.

Enhanced photocatalytic reduction of CO2 to CO over BiOBr assisted by phenolic resin-based activated carbon spheres

Photocatalytic reduction of CO₂ using solar energy to decrease CO₂ emission is a promising clean renewable fuel production technology. Recently, Bi-based semiconductors with excellent photocatalytic activity and carbon-based carriers with large specific surface areas and strong CO₂ adsorption capacity have attracted extensive attention. In this study, activated carbon spheres (ACSs) were obtained via carbonization and steam activation of phenolic resin-based carbon spheres at 850 °C synthesized by suspension polymerization. Then, the BiOBr/ACSs sample was successfully prepared via a simple impregnation method. The as-prepared samples were characterized by XRD, SEM, EDX, DRS, PL, EIS, XPS, BET, CO₂ adsorption isotherm and CO₂-TPD. The BiOBr and BiOBr/ACSs samples exhibited high CO selectivity for photocatalytic CO₂ reduction, and BiOBr/ACSs achieved a rather higher photocatalytic activity (23.74 μmol g⁻¹ h⁻¹) than BiOBr (2.39 μmol g⁻¹ h⁻¹) under simulated sunlight irradiation. Moreover, the analysis of the obtained results indicates that in this photocatalyst system, due to their higher micropore surface area and larger micropore volume, ACSs provide enough physical adsorption sites for CO₂ adsorption, and the intrinsic structure of ACSs can offer effective electron transfer ability for a fast and efficient separation of photo-induced electron–hole pairs. Finally, a possible enhanced photocatalytic mechanism of BiOBr/ACSs was investigated and proposed. Our findings should provide new and important research ideas for the construction of highly efficient photocatalyst systems for the reduction of CO₂ to solar fuels and chemicals.

Photocatalytic reduction of CO₂ using solar energy to decrease CO₂ emission is a promising clean renewable fuel production technology.

Multifunctional property exploration: Bi4O5I2 with high visible light photocatalytic performance and a large nonlinear optical effect

Exploration of the versatility of materials is very important for increasing the utilization of materials. Herein, we successfully prepared Bi₄O₅I₂ powders via a facile solvothermal method. The Bi₄O₅I₂ photocatalyst exhibited significantly higher photocatalytic activity as compared to the common BiOI photocatalyst in the degradation of methyl orange, methylene blue and rhodamine B under visible light irradiation. Especially, for the degradation of methyl orange, the photocatalytic activity of Bi₄O₅I₂ is about 10 times that of BiOI. Moreover, Bi₄O₅I₂ exhibits an extremely high second harmonic generation response of about 20 × KDP (the benchmark) estimated by the unbiased ab initio calculations. The coexisting multifunction of Bi₄O₅I₂ is mainly because of the increased dipole moment due to the stereochemical activity of lone pairs that promotes separation and transfer of photogenerated carriers, then enhances the photocatalytic activity and results in a high second harmonic generation response. This indicates that Bi₄O₅I₂ may have good potential applications in photocatalytic and nonlinear optical fields.

Bi₄O₅I₂ exhibits an extremely high second harmonic generation response and enhanced photocatalytic activity. The multifunction of Bi₄O₅I₂ is mainly resulting from the dipole moment of the stereochemical activity of Bi 6s lone pairs.

Ultrasound assisted synthesis of Bi2NbO5F/rectorite composite and its photocatalytic mechanism insights

Enhancing the adsorbability of the photocatalysts is an effective way to improve the photocatalytic performance. Herein, we firstly synthesized a novel Bi₂NbO₅F/rectorite (BF/R) composite photocatalyst with high adsorption capacity via the ultrasound assisted route. The X-ray photoelectron spectrometer (XPS) analysis has demonstrated that the Bi₂NbO₅F and rectorite were connected with each other by weak chemical bonds. The introduced rectorite in the composite provided rich adsorption active sites for the adsorption of rhodamine B (RhB). The catalytic activity of the BF/R catalyst was evaluated by degrading RhB (5 mg/L) under UV-light irradiation. The BF/R composite with 32% rectorite exhibited the best photocatalytic degradation efficiency for degrading RhB in aqueous solution, which was 6.6 times higher than that of the bare BF sample. The improved activity of the BF/R composite can be ascribed to its strong adsorbability and enhanced light absorption. More importantly, the BF/R catalyst still showed good stability and high activity for degrading RhB after four recycles. Lastly, a possible photocatalytic mechanism on the BF/R composite was proposed. This work would provide helpful insights into the synthesis of the clay combined with Bi-based adjustable structure materials via ultrasound method.

Room-temperature fabrication of bismuth oxybromide/oxyiodide photocatalyst and efficient degradation of phenolic pollutants under visible light

Bismuth oxybromide/oxyiodide (Bi₄O₅Br_xI_2-x) photocatalysts were successfully fabricated using a facile homogeneous precipitation method at room temperature. The obtained Bi₄O₅Br_xI_2-x demonstrated highly enhanced visible-light performances compared with Bi₄O₅Br₂ and Bi₄O₅I₂. The poducts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM). The DRS analysis shows that the band gap structures of Bi₄O₅Br_xI_2-x have been gradually modulated by changing the Br/I molar ratio. The obtained Bi₄O₅Br_xI_2-x samples have exhibited efficient photocatalytic activities in decomposing resorcinol, o-phenylphenol, and 4-tert-butylphenol. The Br/I molar ratio has great influence on the activity of the photocatalysts, and Bi₄O₅Br_0.6I_1.4 exhibited the best activity which was about 2.77 and 1.80 times higher than that of Bi₄O₅Br₂ and Bi₄O₅I₂, respectively. The degradation intermediates were identified by liquid chromatography-mass spectrometry (LCMS), and the possible degradation pathway of resorcinol over Bi₄O₅Br_xI_2-x photocatalysts was proposed. The strong visible light absorption, high charge separation efficiency, and proper band potentials should be responsible for the excellent activity of Bi₄O₅Br_xI_2-x photocatalyst. Trapping experiments using radical scavengers confirmed the generation of O₂^-, OH, and h⁺, but only O₂^- and h⁺ have played the chief role in removing organic pollutants from water.

Fabrication and Photocatalytic Property of Novel SrTiO3/Bi5O7I Nanocomposites

The novel SrTiO3/Bi5O7I nanocomposites were successfully fabricated by a thermal decomposition approach. The as-prepared samples were characterized by XRD, XPS, SEM, EDS, FTIR, DRS and PL spectra. The results show that the SrTiO3/Bi5O7I nanocomposites are composed of perovskite SrTiO3 nanoparticles and tetragonal Bi5O7I nanorods. The SrTiO3/Bi5O7I nanocomposites exhibit an excellent photocatalytic performance for the degradation of RhB solution under simulated solar light irradiation, which is superior to that of pristine Bi5O7I and SrTiO3. In particular, the 30 wt% SrTiO3/Bi5O7I nanocomposite is found as the optimal composites, over which the dye degradation reaches 89.6% for 150 min of photocatalysis. The photocatalytic degradation rate of the 30 wt% SrTiO3/Bi5O7I nanocomposite is found to be 3.97 times and 12.5 times higher than that of bare Bi5O7I and SrTiO3, respectively. The reactive species trapping experiments suggest that [Formula: see text] and holes are the main active species responsible for the RhB degradation. In addition, the PL spectra elucidate the effective separation of photoinduced electron-hole pairs. Further, the possible photocatalytic mechanism of the SrTiO3/Bi5O7I nanocomposites is also elucidated based on the experimental evidences.

Three-dimensional Ag2O/Bi5O7I p-n heterojunction photocatalyst harnessing UV-vis-NIR broad spectrum for photodegradation of organic pollutants

Ag₂O nanoparticles-loaded Bi₅O₇I microspheres forming a three dimensional Ag₂O/Bi₅O₇I p-n heterojunction photocatalyst with wide-spectrum response were synthesized in this study. The results of transmission electron microscopy observations revealed that the Ag₂O nanoparticles with the diameter of ca. 10-20nm were distributed on the surfaces of Bi₅O₇I nanosheets. The as-synthesized Ag₂O/Bi₅O₇I exhibited an excellent wide-spectrum response to wavelengths ranging from ultraviolet (UV) to near-infrared (NIR), indicating its potential for effective utilization of solar energy. Compared with pure Bi₅O₇I, the Ag₂O/Bi₅O₇I composite also demonstrated excellent photocatalytic activity for the degradation of Bisphenol A and phenol in aqueous solution under visible LED light irradiation. Among samples, the 20% Ag₂O/Bi₅O₇I composite photocatalyst showed the highest photocatalytic activity for the degradation of Bisphenol A and phenol in aqueous solution. In addition, the 20% Ag₂O/Bi₅O₇I composite also exhibited a photocatalytic activity for the degradation of Bisphenol A under NIR light irradiation. The improved photocatalytic activity is attributed to the formation of a p-n heterojunction between Ag₂O and Bi₅O₇I, allowing the efficient utilization of solar energy (from UV to NIR) and high separation efficiency of photogenerated electron-hole pairs. The present work is desirable to explore a possible avenue for the full utilization of solar energy.

Bi metal-modified Bi4O5I2 hierarchical microspheres with oxygen vacancies for improved photocatalytic performance and mechanism insights

In this work, we firstly synthesized metallic Bi-modified Bi₄O₅I₂ nanocomposites with oxygen vacancies via a facile one-pot solvothermal method.

Photocatalytic reduction of CO2with H2O vapor under visible light over Ce doped ZnFe2O4

The schematic mechanism of CO₂photoreduction with H₂O vapour over Ce doped ZnFe₂O₄.

Facet-Dependent Photocatalytic N2 Fixation of Bismuth-Rich Bi5O7I Nanosheets

Bismuth-rich bismuth oxyhalides (Bi-O-X; X = Cl, Br, I) display high photocatalytic reduction activity due to the promoting conduction band potential. In this work, two Bi₅O₇I nanosheets with different dominant facets were synthesized using either molecular precursor hydrolysis or calcination. Crystal structure characterizations, included X-ray diffraction patterns (XRD), field emission electron microscopy and fast Fourier transformation (FFT) images, showed that hydrolysis and calcination resulted in the dominant exposure of {100} and {001} facets, respectively. Photocatalytic data revealed that Bi₅O₇I-001 had a higher activity than Bi₅O₇I-100 for N₂ fixation and dye degradation. Photoelectrochemical data revealed that Bi₅O₇I-001 had higher photoinduced carrier separation efficiency than Bi₅O₇I-100. The band structure analysis also used to explain the underlying photocatalytic mechanism based on the different conduction band position. This work presents the first report about the facet-dependent photocatalytic performance of bismuth-rich Bi-O-X photocatalysts.