Chemical Engineering Journal, Vol.281, 102-108, 2015
A simple route to significant enhancement of photocatalytic water oxidation on BiVO4 by heterojunction with SiC
Highly-efficient photocatalysts are essential to produce clean energy from water using solar energy source. They play a key role in promoting the catalytic reactions. However, development of low-cost and eco-friendly catalysts for water oxidation process is still challenging. Herein we show that the photocatalytic activity of BiVO4 can be greatly enhanced by compositing SiC micro-sized powder to form well-connected interfaces via crystal engineering method. The rate of photocatalytic oxygen evolution is doubled, leading to 659 mu mol h(-1) g(-1) observed in 1:1 (weight ratio) SiC/BiVO4 composites under visible-light irradiation, even though SiC itself is very passive in O-2 production. The apparent quantum efficiency reaches 1.04% at 420 nm. The transfer pathway of the photo-generated electrons between the composite is facilitated through a Z-scheme contact between BiVO4 and SiC, which is further evidenced by using H2PtCl6 photo-reduction as a molecular probe. Our method provides a simple and practical route to enhance and improve the catalytic activity for the existing catalysts by using low-cost and environmental-friendly non-metal materials. (C) 2015 Elsevier B.V. All rights reserved.