Enhancing light-driven photocatalytic reactions through solid solutions of bismuth oxyhalide/bismuth rich photocatalysts: a systematic review

The pursuit of sustainable environmental remediation strategies has led to intensive research in photocatalysis. Photocatalysts are a class of compounds with exceptional properties, making them suitable for various applications in environmental remediation. They are effective against multiple organic and inorganic pollutants and are also used as semiconductors for green energy production. Among the various photocatalytic semiconductor materials explored, bismuth oxyhalide (BiOY, Y = F, Cl, Br, or I) and bismuth-rich (Bi_xO_yY_z, Y = F, Cl, Br, or I) are particularly notable. However, unmodified/pristine BiOY and Bi_xO_yY_z exhibit inherent limitations of low photocatalytic performance owing to unsuitable band gaps and low efficiency in separating carriers. Hence, this review outlines the BiOY and Bi_xO_yY_z structures, wherein modifiable halogen layers may offer favorable conditions for creating solid solutions with improved intrinsic properties and catalytic performance. This systematic review also explores the unique attributes and challenges associated with tuning the photocatalytic performance of BiOY and Bi_xO_yY_z solid solutions to enhance solar-driven reactions. The distinctive feature of this review lies in the versatile nature of the BiOY and Bi_xO_yY_z solid solution materials. These materials offer the advantage of harnessing a broad light spectrum, including solar and UV radiation. This review further explores the strategies and techniques employed to optimize BiOY and Bi_xO_yY_z photocatalysts by forming solid solution and their application in water treatment processes. Furthermore, it highlights the ongoing challenges and opportunities in developing high-performance BiOY and Bi_xO_yY_z solid solution photocatalysts, illustrating their potential to drive a more sustainable and energy-efficient future through enhanced light-driven reactions.