Reduced graphene oxide decorated SnO2/BiVO4 photoanode for photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting technology offers a sound strategy for the production of chemical energy using abundant solar energy. Herein, a ternary photoanode of SnO2/BiVO4/rGO was fabricated by plain chemical vapor deposition (CVD) and metal-organic decomposition followed by spin-coated rGO on the SnO2/BiVO4 junction. The ternary photoanode yields the highest photocurrent density of 2.05 mA cm(-2) at 1.23 V vs. RHE, which is 3.73 times of the BiVO4 photoanode (0.55 mA cm(-2)). The incident photon-to-electron conversion efficiency (IPCE) of the ternary photoanode is 2.47 times that of the BiVO4 photoanode at 400 nm, and the onset potential exhibits a cathodic shift of similar to 300 mV. This enhancement can be attributed to the formation of n-n heterojunctions between the SnO2 and BiVO4, and decoration of rGO on said heterojunctions because they synergistically improve the absorption of visible light, enhance the efficiency of charge separation, and accelerate electron transfer at the electrode/electrolyte interface. (C) 2020 Published by Elsevier B.V.