Bi4O5Br2-based photocatalysts for multifunctional applications: Band engineering, synthesis, and photocatalytic performance

Photocatalysis is an emerging technology that harnesses solar energy to tackle energy storage and environmental issues. Among various photocatalysts, Bismuth oxybromide (Bi 4 O 5 Br 2 ) received much attention due to its finite visible light efficiency, good electrical conductivity, tunable morphology and optimal bandgap, making it suitable for various applications. Hence, Bismuth oxybromide has undergone optimisation and extensive modification to enhance its photocatalytic activity. The photocatalytic mechanism and crystalline properties are contemplated by XRD and DFT calculations. This review delivers a comprehensive overview of the recent progress of the Bi 4 O 5 Br 2 photocatalyst with its crystallographic structure. The synthesis processes of Bi 4 O 5 Br 2 – based photocatalyst are demonstrated, which include solvothermal, hydrothermal, hydrolysis method, microwave heating method, as well as microemulsion method. Further, we emphasised modification strategies to enhance photocatalytic performance, such as doping, surface defect and heterojunction formation. Subsequently, Bi 4 O 5 Br 2 -based material and its potential application in environmental remediation: photodegradation of dyes, antibiotics, organic pollutants and heavy metal removal and energy conversion, such as photocatalytic water splitting for H₂ evolution and CO₂ reduction. Lastly, we conclude possible challenges and Future Perspectives associated with the Bi 4 O 5 Br 2 -based photocatalyst.