Superiority of graphene over carbon analogs for enhanced photocatalytic H2-production activity of ZnIn2S4

Graphene and its derivative reduced graphene oxide (RGO) have been widely considered to be a miracle modifier for most semiconductor photocatalysts over the past decade. However, the underlying advantage of graphene over its carbon analogs was rarely studied under the same experimental conditions to reveal its uniqueness. In this study, the promotion effect of RGO on ZnIn2S4 (ZIS) semiconductor photocatalyst was systemically compared with that of carbon quantum dots (CQDs) and carbon nanotubes (CNTs). According to the property-photoactivity correlation analysis, the primary roles of these carbon analogs displayed an obvious dissimilarity. Among them, RGO manifested its superiority in enhancing the photoactivity of ZIS for hydrogen production from water splitting via controlling the morphology and boosting the charge carrier transferring. Our work revealed the exact contributions of different carbon materials to the promoted physicochemical properties and photocatalytic H-2-production activity of ZIS semiconductor, and further affirmed the superiority of RGO over its carbon analogs in the construction of high-efficiency carbon-semiconductor based composite photocatalysts. (C) 2017 Elsevier B.V. All rights reserved.