Visible Photocatalytic Activity Enhancement of ZnWO4 by Graphene Hybridization

ZnWO 4 /graphene hybride (GZW-X) photocatalysts were synthesized via a facile in situ reduction of graphene oxide and ZnWO 4 in water. High efficiency for the degradation of methylene blue (MB) under both UV light and visible light was obtained for the GZW-X photocatalysts. The photocatalytic efficiency of ZnWO 4 /graphene-0.2 wt % under visible-light and UV-light irradiation was ∼7.1 and 2.3 times that of pristine ZnWO 4, respectively. The visible photocatalytic activity originated from the • OH and O 2 •–, which were formed by photosensitization of graphene in ZnWO 4 /graphene. The enhancement of UV photocatalytic light activity in ZnWO 4 /graphene was attributed to the high separation efficiency of photoinduced electron–hole pairs resulting from the promotion of HOMO orbit of graphene in ZnWO 4 /graphene.