Fabrication of graphene/CaIn2O4 composites with enhanced photocatalytic activity from water under visible light irradiation

• G/CIO composites were synthesized by a facile solvothermal method.
• The photocatalytic activities were studied under visible light irradiation.
• The introduction of graphene can enhance the photocatalytic activity of CIO.
• G1/CIO composite exhibited the best photocatalytic activity.
• G1/CIO composite could evolve H2 stably for 32 h without deactivation.

A series of graphene/CaIn2O4 composites were synthesized using a facile solvothermal method to improve the photocatalytic performance of CaIn2O4. The reduction of graphene oxide to graphene and the deposition of CaIn2O4 nanoparticles on the graphene sheets can be achieved simultaneously during the solvothermal process. The photocatalytic activities of as-prepared graphene/CaIn2O4 composites for hydrogen evolution from CH3OH/H2O solution were investigated under visible light irradiation. It was found that graphene exhibited an obvious influence on the photocatalytic activity of CaIn2O4. The graphene/CaIn2O4 composite reached a high H2 evolution rate of 62.5 μmol h−1 from CH3OH/H2O solution when the content of graphene was 1 wt%. Furthermore, the 1 wt% graphene/CaIn2O4 composite did not show deactivation for H2 evolution for longer than 32 h. This work could provide a new insight into the fabrication of visible light driven photocatalysts with efficient and stable performance.