Visible Photocatalytic\nActivity Enhancement of ZnWO₄ by Graphene Hybridization

Abstract

ZnWO₄/graphene hybride (GZW-X) photocatalysts\nwere synthesized\nvia a facile in situ reduction of graphene oxide and ZnWO₄ in water. High efficiency for the degradation of methylene blue\n(MB) under both UV light and visible light was obtained for the GZW-X\nphotocatalysts. The photocatalytic efficiency of ZnWO₄/graphene-0.2\nwt % under visible-light and UV-light irradiation was ∼7.1\nand 2.3 times that of pristine ZnWO_4, respectively. The\nvisible photocatalytic activity originated from the ^•OH and O₂^•–, which were formed\nby photosensitization of graphene in ZnWO₄/graphene. The\nenhancement of UV photocatalytic light activity in ZnWO₄/graphene was attributed to the high separation efficiency of photoinduced\nelectron–hole pairs resulting from the promotion of HOMO orbit\nof graphene in ZnWO₄/graphene.