Recent advancements in bismuth vanadate photoanodes for photoelectrochemical water splitting

Efficient solar fuel production is indispensable for achieving a sustainable and carbon-neutral society. Photoelectrochemical (PEC) water splitting provides a promising technique for converting solar energy to sustainable hydrogen. Limited by the rate-determining oxygen evolution reaction (OER), the development of efficient photoanodes is crucial for overall PEC performance. Among the potential photoanode candidates, bismuth vanadate (BiVO4) has recently raised widespread attention owing to the suitable bandgap, cost-effectiveness, and chemical stability. However, the insufficient light absorption, poor charge transport properties and sluggish surface reaction render the efficient PEC solar hydrogen production an unsolved and ongoing challenge. Therefore, considerable efforts have been devoted to meeting this challenge. In this review, recent advancements in BiVO4 photoanodes have been summarized. Subsequently, effective strategies for improving light absorption, charge separation and transport, surface reaction, and long-term stability are introduced. In addition, unassisted tandem devices for PEC water splitting are also discussed. This review provides a survey of relevant PEC water splitting systems from past to present and outlooks on the future scale-up based on BiVO4 photoanodes, with particular focus on the breakthroughs of photoanodes design and systems integration.