Al-O bridged NiFeO /BiVO4 photoanode for exceptional photoelectrochemical water splitting

Developing BiVO4 photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical (PEC) water splitting. The capacity to increase the PEC activity of BiVO4 by loading oxygen evolution co-catalysts (OECs) has been proven, however it suffers from sluggish charge carriers dynamics brought on by the complicated interface between BiVO4 and OECs as well as poor long-term durability. Herein, we connected OECs (NiFeOx) and photoanode with a Al-O bridge for bettering the PEC performance of BiVO4. The Al-O bridge served as a channel to extract hole from BiVO4 to NiFeOx, thus boosting charge carriers′ separation and preventing BiVO4 from photo-corrosion. The Al-O bridging photoanode (NiFeOx/Al2O3/BiVO4) demonstrated a high photocurrent density of 5.87 mA/cm2 at 1.23 V vs. RHE and long-term photostability in comparison to NiFeOx/BiVO4 photoanode. This study proposes a unique technique to boost charge carriers′ separation between BiVO4 and OECs for high-efficiency solar-driven PEC water splitting.