Bimetallic Bismuth-Based Oxyhalides for Photocatalysis

Bismuth-based bimetallic oxyhalide photocatalysts possess tunable electronic configurations, unique layered crystal structure and outstanding photoelectric properties, thus delivering prominent photocatalytic performance. This review systematically summarizes the latest research advances in structural design and regulation of various bismuth-based bimetallic oxyhalides for improving photocatalytic conversion efficiency. According to material categories, this review first classifies as bismuth-based Sillén-Aurivillius phase bimetallic oxyhalides, lead-bismuth-based oxyhalides, and cadmium-bismuth-based oxyhalides, and sorts out the research status of this series of photocatalytic materials. The modification methods for optimizing the photocatalytic performance of bismuth-based bimetallic oxyhalides are presented, including morphological regulation, surface functional loading modification, cocatalyst loading, defect engineering, element doping, crystal facet exposure, and heterojunction construction, with the emphasis of structure-activity relationship. Then, diverse photocatalytic applications of bismuth-based bimetallic oxyhalides are introduced, such as photocatalytic water splitting, photocatalytic oxygen evolution, photocatalytic organic syntheses, photocatalytic CO₂ reduction, and photocatalytic pollutant removal. Finally, the development limitations and future optimization directions in this research field are also prospected.