Alternative strategies in improving the photocatalytic and photoelectrochemical activities of visible light-driven BiVO₄: A review

The research interest on bismuth vanadate (BiVO₄) has heightened over the past decade due to its proven high activity for water oxidation and organic degradations under visible light. Although metal doping and water-oxidation cocatalyst loading have been widely demonstrated to be useful to overcome the poor electron transport and slow water oxidation kinetics of BiVO₄, the efficiency of this material is still greatly limited by poor charge separation. Various efforts directed at modifying the surface and bulk properties to improve the performance of BiVO₄-based materials have therefore been developed, including crystal facet engineering, coupling with graphitic carbon material, annealing treatment, and nanoscaling. This review aims to provide insights into the most recent progress in these strategies in regard to their influences on the charge separation, transport, and transfer aspects of BiVO₄, all of which are crucial to govern photochemical conversion efficiency. Understanding of these charge kinetics in relation to the properties of BiVO₄ is of fundamental importance for rational design of BiVO₄ with optimum structures, which may serve as a general guideline for the fabrication of metal oxide photocatalysts.