BiVO4/g-C3N4 composite visible-light photocatalyst for effective elimination of aqueous organic pollutants

BiVO4/g-C3N4 composite photocatalysts were successfully synthesized by sonification and the chemical structures of BiVO4/g-C3N4 heterostructures are characterized systematically. The photocatalytic activity of BiVO4/g-C3N4 for rhodamine B (RhB) and p-nitrophenol (PNP) degradation is evaluated under visible light irradiation. It has been found that the novel BiVO4/g-C3N4 composites exhibit excellent catalytic activities towards RhB and PNP degradation, and these BiVO4/g-C3N4 composites are much more active compared with that of pure g-C3N4. Activity enhancement after BiVO4 introducing is mainly attributed to the better optical absorption ability over the well contacted structure in heterojunctions, good adsorption ability of organic contaminants and lower recombination rate of electron-hole pairs. In addition, in BiVO4/g-C3N4-based visible-light system center dot OH radical, not active in pure g-C3N4 system, is also found to be active species for pollutants degradation, which may be another evidence for the enhanced photocatalytic activity by BiVO4 introduction. Furthermore, the most active 10 wt.% BiVO4/g-C3N4 photocatalyst exhibits enough catalytic stability in recycle test, showing great potential as cost-effective heterogeneous visible-light photocatalyst for aqueous organic contaminants elimination in future applications. (C) 2016 Published by Elsevier B.V.