Novel bismuth sulfhalide photocatalysts: from structural design to energy and environmental applications

Novel bismuth sulfhalide photocatalysts (such as Bi₁₉S₂₇X₃, X = Cl, Br, I), as a unique family of semiconductors, have emerged as a new focus in photocatalytic research due to their tunable electronic structures, unique charge polarization effects, and multidimensional interface engineering capabilities. This review systematically outlines various synthesis methods of bismuth sulfhalide materials, from traditional hydrothermal approaches to microwave-assisted aqueous synthesis and colloidal chemistry synthesis, highlighting the crucial role of these methods in controlling material morphology and structure. Furthermore, the review delves into various photocatalytic performance optimization strategies, such as defect engineering, heterostructure construction, interface regulation, and morphology control, which significantly enhance the materials' light absorption capacity, charge separation efficiency, and surface reaction activity. Finally, this review provides a detailed summary of the latest advancements across various fields of photocatalytic applications, showcasing their broad potential in CO₂ reduction, H₂ production, H₂O₂ synthesis, NH₃ synthesis and pollutant degradation. Future research should focus on scalable production, long-term stability, in situ mechanism analysis, and applications for fine chemical synthesis to promote the further development of bismuth sulfhalide-based photocatalysts.