Recent Advances in Photocatalytic Mechanisms of Bismuth Vanadate Defect Engineering and Heterojunction Synergistic Effects

ABSTRACT Bismuth vanadate (BiVO 4 ), as a visible‐light‐responsive photocatalyst, suffers from limited catalytic efficiency due to its rapid electron–hole recombination rate and narrow light absorption range. To address these issues, defect engineering and heterojunction construction have been widely explored; however, systematic studies on their synergistic effects remain scarce. This review summarizes the physicochemical fundamentals underlying the synergistic interaction between oxygen vacancies, elemental doping, and heterojunctions in BiVO 4 (where defects regulate the type and concentration of intrinsic vacancies, and heterojunctions facilitate charge carrier separation). It further discusses strategies for dynamic modulation of oxygen vacancies and performance optimization (since oxygen vacancies can tune the band structure and extend the light absorption range of BiVO 4 ), as well as multiscale (atomic, nanoscale, and microscale) structural design principles. The analysis reveals that the synergistic mechanism between defects and heterojunctions lies in the role of oxygen vacancies as charge transport “bridges” to accelerate electron transfer, while elemental doping‐induced heterojunctions promote band alignment optimization. Accordingly, a band‐defect‐interface integrated design framework and a correlation mechanism between dynamic defects and interfacial reactions are proposed. Finally, the review outlines future research perspectives for BiVO 4 ‐based photocatalysts.