▎ 摘　　要

Reduced graphene oxide (RGO)/ZnIn2S4 nanocomposites with RGO in different reduction degrees have been prepared and their photocatalytic performance for H-2 evolution under visible light irradiation has been evaluated. The reduction degree of RGO in the RGO/ZnIn2S4 nanocomposite synthesized via a direct hydrothermal process was low and the resultant RGO/ZnIn2S4-hydrothermal exhibited lower photocatalytic performance for H-2 evolution even when compared to pure ZnIn2S4. The reduction degree of RGO in the RGO/ZnIn2S4 nanocomposite can be increased by a further photoreduction or hydrazine reduction. These highly reductive RGO/ZnIn2S4 nanocomposites showed significantly enhanced photocatalytic activity for H-2 production under visible light irradiation. Highly reduced RGO in the RGO/ZnIn2S4 nanocomposites serves as a good electron acceptor/mediator as well as the H-2 evolution site to promote the photocatalytic water splitting over ZnIn2S4. A correlation between the photocatalytic performance for H-2 evolution and the RGO reduction degree over RGO/ZnIn2S4 nanocomposites was shown for the first time. This study provides new insights in the developments of RGO-based nanocomposite materials for photocatalytic applications.