Enhanced Photoelectrochemical Water Splitting and Photocatalytic Water Oxidation of Cu2O Nanocube-Loaded BiVO4 Nanocrystal Heterostructures

Reducing the fast recombination of photogenerated electron-hole pairs of semiconductor photocatalyst is very important to improve its photocatalysis. In this paper we fabricate Cu2O nanocube-decorated BiVO4 nanocrystal (denoted as BiVO4@Cu2O nanocrystal@nanocube) heterostructure photocatalyst by coupling n-type BiVO4 with p-type Cu2O. The BiVO4@ Cu2O nanocrystal@nanocube photocatalysts show superior photocatalytic activities in photoelectrochemical (PEC) activity and photocatalytic water oxidation to BiVO4 photocatalysts under visible light illumination. The BiVO4@Cu2O nanocrystal@ nanocube heterostructure electrode achieves the highest photocurrent density of similar to 10 mu A cm(-2) at 0 V versus Ag/AgCl, 5 times higher than that of BiVO4 nanocrystal electrode (similar to 2 mu A cm(-2)). The light induced evolution rate of O-2 generation for BiVO4@Cu2O nanocrystal@ nanocube heterostructures is as high as 150 mu mol h(-1) 100 mg cat(-1), more than 3 times higher than that (48 mu mol h(-1) 100 mg cat(-1)) of BiVO4 nanocrystals. The enhanced photocatalysis activities of the BiVO4@Cu2O nanocrystal@ nanocube photocatalysts are attributed to the efficient separation of the photoexcited electron-hole pairs caused by inner electronic field (IEF) of p-n junction. This study opens up new opportunities in designing photoactive materials with highly enhanced performance for solar energy conversion.