Doping Engineering in BiVO 4 Photoanodes: From Electronic Structure Modulation to Multiscale Regulation of Photoelectrochemical Water Splitting

ABSTRACT Bismuth vanadate (BiVO 4 ) is a promising photoanode for photoelectrochemical (PEC) solar hydrogen production; however, its performance is limited by poor carrier mobility, short diffusion length, and sluggish oxygen evolution reaction (OER) kinetics. Doping engineering has emerged as an effective, scalable, and versatile strategy to address these limitations by enabling the coordinated modulation of electronic structure, defect chemistry, and interfacial properties. This review provides a systematic and application‐oriented perspective on doping engineering in BiVO 4 photoanodes. It first elucidates the fundamental mechanisms of doping, including dopant site selection, electronic structure modulation, charge carrier dynamics, and interfacial catalytic regulation. It then summarizes recent advances in metal doping, non‐metal doping, and co‐doping strategies, highlighting their roles in achieving multiscale performance optimization. Advanced concepts, including dopant‐defect coupling, strain‐induced electronic reconstruction, and gradient doping, are further discussed as emerging strategies for enabling cross‐scale regulation. Doping methodologies, including in situ synthesis, electrochemical treatment, plasma‐assisted modification, and interfacial engineering, are also discussed from the perspective of controllability, scalability, and structure‐function relationships. Finally, key challenges and future directions for developing integrated, durable, and scalable PEC systems are outlined. This review provides general design principles for rational doping engineering and offers guidance for the development of solar‐to‐hydrogen conversion technologies.