BiVO₄-Based Photoanodes for Solar Fuel Production: From Bulk Doping to Multiphase Integrated Architectures

Bismuth vanadate (BiVO₄) is a promising photoanode for photoelectrochemical (PEC) solar fuel production owing to its visible-light response and suitable band structure. However, its efficiency is still limited by poor charge mobility, severe bulk/surface recombination, and sluggish interfacial oxidation kinetics. Compared with recent reviews mainly focused on water oxidation or individual modification strategies, this review links defect chemistry, charge-carrier dynamics, interfacial kinetics, operational stability, and coupled solar fuel production. Particular attention is given to vacancy engineering, advanced transient and in situ characterization, and the integration of BiVO₄-based photoanodes into PEC CO₂ reduction and high-value chemical synthesis systems. Finally, key challenges related to long-term stability, scalable fabrication, and practical device integration are discussed, providing guidance for the design of efficient and durable BiVO₄-based photoelectrodes.