BiOCl Nanoflowers with High Levels of Oxygen Vacancy for Photocatalytic CO₂ Reduction

Abstract

CO 2 photoreduction products, such as CO and CH 4 , have the potential to be further processed into valuable products and fuels, making this process a promising, environmentally friendly, and economically viable energy conversion technology. In this study, uniform BiOCl hierarchical nanoflowers with tunable thickness and abundant oxygen vacancies (OVs) were synthesized using a poly(vinylpyrrolidone)/ethylene glycol-assisted self-assembly method. The OV-rich BiOCl nanoflower (BiOCl-3) showed a 4-fold increase in photocatalytic conversion of CO 2 to CO compared to BiOCl nanosheets (BiOCl-1). Density functional theory (DFT) calculations and energy band analysis reveal anisotropy in the CO 2 reduction activity across different crystal facets, and the morphology can affect both the conduction band (CB) and band gap, resulting in a more negative CB edge for BiOCl compared to the reduction potential of CO 2 photoreduction to CO. This work provides a comprehensive analysis and explanation of the OV-rich BiOCl photocatalytic CO 2 reduction from both experimental and theoretical perspectives.

Dual-Defective Two-Dimensional/Two-Dimensional Z-Scheme Heterojunctions for CO2 Reduction

“…Overall, in this study, CO 2 adsorption followed by hydrogenation to COOH is the ratedetermining step. 62 The energy barrier of the heterojunction with both N vacancies from ns-CN and O vacancies from BiOCl is lower than that of the ns-CN and the heterojunction without vacancies, indicating a thermodynamic preference for CO release on the OVs-BiOCl/ns-CN heterojunction.…”

Urchin-like TiO2/CdS Nanoparticles Forming an S-scheme Heterojunction for Photocatalytic Hydrogen Production and CO2 Reduction

“…To further improve the photocatalytic ability of TiO 2 , researchers recently studied a series of new catalysts for photocatalytic H 2 and CO 2 reduction reactions, such as 3D/2D TiO 2 @Ti 3 C 2 MXene/Bi 2 S 3 , TiO 2 /C 3 N 4 , 3D ZnIn 2 S 4 /TiO 2 and so on. Of course, some scholars use the advantages of precious metals in catalysis to improve the performance of catalysts by incorporating Pt, Au, and Ag. , In addition, the performance of the TiO 2 catalyst was also improved by designing the morphology of composite materials, , Z-scheme heterojunctions, , and p–n heterojunctions . However, there are few research studies on S-scheme heterojunction catalysts constructed with cheap inorganic materials and even fewer research studies on catalysts that can photocatalyze both H 2 production and CO 2 reduction …”

BiOCl Nanosheets with (001), (002), and (003) Dominant Crystal Faces with Excellent Light-Degradation Ability

“…When the modification of bismuth oxyhalide itself is studied, it is mainly through the introduction of oxygen vacancies and the increase of specific surface area − and it is believed that the existence of oxygen vacancies plays a decisive role in the activity of photocatalysts . Oxygen vacancies can enhance the oxidation reduction capacity of catalysts, and large specific surface areas can provide more active sites.…”