2D/3D WO3/BiVO4 heterostructures for efficient photoelectrocatalytic water splitting

Developing novel photoanodes with high efficiency for photoelectrochemical (PEC) water splitting has become the key to solar energy conversion and storage realm. Herein, 3D worm-like bismuth vanadate (BiVO 4 ) is grafted on 2D thin tungsten trioxide (WO 3 ) underlayer by electrodeposition to form mixed–dimensional structured photoanode, resulting in significant improvement of the photocatalytic performance and the charge separation efficiency. Characterization results prove that the mixed–dimensional structured can boost the photocatalytic activity by suppressing back reaction and charge recombination of the bulk BiVO 4 . Simultaneously, the electrical conductivity of photoanode can be increased by W 6+ doping. Furthermore, a robust catalyst NiCo 2 O x is coated onto the surface of WO 3 /BiVO 4 photoanode, exhibiting a desirable photocurrent of 3.85 mA cm −2 at 1.23 V vs . RHE and an excellent stability over 3 h. Both the excellent photocurrent density and great operational stability of this 2D/3D WO 3 /BiVO 4 photoanode make it a promising material for practical applications.