title: A high-performance Bi2WO6-graphene photocatalyst for visible light-induced H2 and O2 generation.
abstract: We developed a highly efficient photocatalyst for both H2 and O2 generation under visible-light irradiation by attaching Bi2WO6 (BWO) nanocrystals on graphene nanosheets to produce a graphene-Bi2WO6 composite (Gr-BWO-T). The composite was prepared by a sonochemical method where graphene oxide (GO) served as the support on which BWO formed in situ. Bi2WO6 nanoparticles with the size of 30-40 nm were homogeneously dispersed on the surface of graphene sheets, due to their bonding with graphene. When used as a photocatalyst under visible-light irradiation, O2 production rate reached a value up to 20.60 μmol h(-1), 4.18 times higher than that of bare BWO, resulting from the strong covalent bonding between graphene and BWO nanoparticles. The chemical bonding facilitated the electron collection and transportation and inhibited the recombination of photo-generated charge carriers, even in this system with a large amount of graphene inside (40 wt%). More interestingly, H2-production by Gr-BWO-T was also observed to be as high as 159.20 μmol h(-1). This could be ascribed to the existence of the graphene that led to decrease in conduction band potential and resulted in a more negative reduction potential than H(+)/H2. This facile sonochemical approach provides a new strategy for engineering ternary compound nanoparticles on graphene sheets, with great potential application in energy conversion.
authors.affiliation: State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China. smzhu@sjtu.edu.cn zhangdi@sjtu.edu.cn.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Sun
authors.forename: Jingjing
authors.initials: J
authors.lastname: Guo
authors.forename: Shenmin
authors.initials: S
authors.lastname: Zhu
authors.forename: Lin
authors.initials: L
authors.lastname: Mao
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008027:Light; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D017973:Tungsten Compounds; D006108:Graphite; D006859:Hydrogen; D010100:Oxygen; D001729:Bismuth