Synergistic Effect of Co(HPO)(OH) Cocatalyst and AlO Passivation Layer on BiVO Photoanode for Enhanced Photoelectrochemical Water Oxidation.

Bismuth vanadate (BVO) is regarded as an exceptional photoanode material for photoelectrochemical (PEC) water splitting, but it is restricted by the severe photocorrosion and slow water oxidation kinetics. Herein, a synergistic strategy combined with a Co(HPO)(OH) (CoPH) cocatalyst and an AlO (ALO) passivation layer was proposed for enhanced PEC performance. The CoPH/ALO/BVO photoanode exhibits an impressive photocurrent density of 4.9 mA cm at 1.23 V and an applied bias photon-to-current efficiency (ABPE) of 1.47% at 0.76 V. This outstanding PEC performance can be ascribed to the suppressed surface charge recombination, facilitated interfacial charge transfer, and accelerated water oxidation kinetics with the introduction of the CoPH cocatalyst and ALO passivation layer. This work provides a novel and synergistic approach to design an efficient and stable photoanode for PEC applications by combining an oxygen evolution cocatalyst and a passivation layer.