A comprehensive review on the synthesis of Bi3O4Br and Bi24O31Br10 photocatalysts and their environmental applications

Bi-rich bismuth oxybromides are good photocatalysts due to their tunable electronic properties and layered structure. Among them, Bi 3 O 4 Br and Bi 24 O 31 Br 10 have attracted growing interest because of their superior light absorption and charge separation capabilities compared to BiOBr. This review provides a comprehensive overview on the synthesis, modification, and environmental applications of these Bi-rich materials. Synthesis methods, such as hydrothermal, solvothermal, ball-milling, and combustion are presented in detail. Strategies for enhancing photocatalytic performance, such as heterojunction formation and doping with metals or non-metals, are also explored. The environmental applications of Bi 3 O 4 Br and Bi 24 O 31 Br 10 , including the degradation of aqueous-phase pollutants, gas-phase environmental applications, and H 2 and O 2 evolution, are discussed. The advancements and challenges in the application of these photocatalysts to environmental applications are discussed together with the potential future developments and research challenges.