Preparation and Insight of [010]‐Orientated BiVO ₄ Planar Photoanode via One‐Step Pyrolysis for Significantly Promoted Charge Separation and Water Oxidation

Abstract Preparation of planar bismuth vanadate (BiVO ₄ , BVO) photoanode has inspired continuous interest due to its simple preparation and easy scalability, but its efficiency is still retarded by the poor bulk charge separation. Herein, BVO photoanode is successfully prepared with a preferential [010] orientation (denoted as [010]‐BVO) grown on fluorine‐doped tin oxide (FTO) through one simple pyrolysis method for the first time, which exhibits over 21 times of higher photocurrent density of water oxidation with respect to the randomly orientated BVO (denoted as R‐BVO). Strikingly, the orientated BVO photoanode shows an exceptional charge separation efficiency of 97.5% at 1.23 V versus the reference hydrogen electrode (RHE) and a theoretical applied bias photon‐to‐current efficiency (ABPE) value of 2.1% at 0.67 V versus RHE. It is unraveled that the significantly increased carrier transport and collection along the [010] direction should be mainly responsible for the unexpectedly efficient charge separation as well as photoelectrochemical performance. The development of orientated growth planar BVO photoanode may pave the way for designing high‐performance photoanodes for large‐scale solar‐to‐chemical conversion.