Recent Progress and Challenges of Bismuth-Based Photocatalysts: Fundamentals and Applications

Photocatalysis is a promising and sustainable approach to converting solar energy into chemical energy, offering a potential candidate to global energy and environmental crises. Bismuth (Bi) based materials have garnered significant attention due to their visible-light-responsive ability, unique layered structure, piezoelectricity, and tunable band structures. However, their practical application is significantly hindered by carrier recombination and slow interfacial reaction kinetics, which are caused by the weak driving forces for photoexcited charge separation and transfer, limited exposure of active sites, and unbalanced adsorption/desorption abilities. This work provides a systematic overview of the structural and electronic properties, synthesis methods, challenges, and applications of Bi-based photocatalysts. Specifically, this work categorizes different types of Bi-based materials and illustrates the origin of their piezoelectricity based on crystallographic structure. Moreover, this review concentrates on modification strategies for Bi-based photocatalysts, including crystal facet engineering, heterojunction construction, defect engineering, and piezoelectric polarization, while highlighting their synergistic effects in the field of pollutant degradation, hydrogen peroxide generation, carbon dioxide reduction, water splitting, and nitrogen fixation. Finally, the challenges and future research directions for developing advanced Bi-based photocatalysts are proposed. This review aims to provide a comprehensive understanding and essential insights to expedite the application of Bi-based nanocomposites in photocatalytic reactions.