Photocatalytic degradation of organic pollutants in wastewater is recognized as a promising technology. However, photocatalyst Bi₂O₃ responds to visible light and suffers from low quantum yield. In this study, the α-Bi₂O₃ was synthetized and used for removing Cl⁻ in acidic solutions to transform BiOCl. A heterostructured α-Bi₂O₃/BiOCl nanosheet can be fabricated by coupling Bi₂O₃ (narrow band gap) with layered BiOCl (rapid photoelectron transmission). During the degradation of Rhodamine B (RhB), the Bi₂O₃/BiOCl composite material presented excellent photocatalytic activity. Under visible light irradiation for 60 min, the Bi₂O₃/BiOCl photocatalyst delivered a superior removal rate of 99.9%, which was much higher than pristine Bi₂O₃ (36.0%) and BiOCl (74.4%). Radical quenching experiments and electron spin resonance spectra further confirmed the dominant effect of electron holes h⁺ and superoxide radical anions ·O₂⁻ for the photodegradation process. This work develops a green strategy to synthesize a high-performance photocatalyst for organic dye degradation.

Photocatalysis is an effective way to alleviate the energy crisis and environmental pollution. Bismuth Chloride Oxide (BiOCl) is one of the most widely studied metal oxides due to its unique surface and electronic structure. However, the wide band gap of BiOCl and the high complexation rate of photogenerated electron–hole pairs limit its photocatalytic efficiency. Increasingly, efforts are being made to improve the performance of this range of photocatalysts. The article reviews the progress of research to enhance the photocatalytic activity of BiOCl nanomaterials. Strategies to improve the photocatalytic performance of single-phase BiOCl include morphological control, component adjustment, crystal facet control, and defects construction. Strategies to improve the photocatalytic activity of BiOCl-based composites include surface modification, immobilization of photocatalysts, impurity doping, and the construction of heterojunctions. In addition, the challenges and trends of BiOCl photocatalysts are discussed and summarized. Hopefully, this review will be helpful for the research and application of BiOCl photocatalysts.

Bismuth chloride oxide (BiOCl) is a typical V-VI-VII ternary oxide material, which is one of the widely studied metal oxides due to its unique surface, electronic and photocatalytic properties. However, the broad bandgap and the large number of photogenerated electron-hole pair complexes of BiOCl limit its photocatalytic efficiency. Since the photocatalytic performance of BiOCl is highly dependent on its exposed crystallographic facets, research attention has increasingly focused on the different structures and properties possessed by different crystallographic facets of BiOCl. This article reviews the basic principles of using different crystalline surfaces of BiOCl materials to enhance photocatalytic activity, summarizes the applications of BiOCl single-crystal catalysts and composite catalysts in the environmental field, and provides an outlook on the challenges and new research directions for future development in this emerging frontier area. It is hoped that the crystalline surface-related photocatalysis of BiOCl can be used to provide new guidance for the rational design of novel catalysts for various energy and environment-related applications.