Highly efficient dual cocatalyst-modified TiO2 photocatalyst: RGO as electron-transfer mediator and MoSx as H2-evolution active site

The rapid interfacial charge transfer and interfacial catalytic reaction are highly desirable to improve the photocatalytic H-2-evolution performance of semiconductor photocatalysts. To achieve the goal, in the paper, MoSx-rGO/TiO2 was synthesized by a facilely two-step photocatalytic reduction approach including reducing GO/TiO2 to rGO/TiO2 and then reducing ammonium tetrathiomolybdate ((NH4)(2)MoS4) to form amorphous MoSx on the rGO surface. In the case, the rGO nanosheets as an electron mediator caused rapid transportation of photogenerated electrons from the conduction band (CB) of TiO2, while amorphous MoSx served as an effective active site for the following interfacial reduction reaction for H-2 evolution. The photocatalytic results indicated that the H-2-evolution rate of synthesized MoSx-rGO/TiO2 was 206.6 mu mol h(-1), which was obviously higher than that of TiO2 (6.9 mu mol h(-1)), rGO/TiO2 (31.8 mu mol h(-1)) and MoSx/TiO2 (150.1 mu mol h(-1)) due to the rapid interfacial charge transfer and interfacial catalytic reaction. Considering the present mild and green approach, the obtained MoSx-rGO/TiO2 could be regarded as a potential photocatalyst for the practical application. In addition, this work also could provide some new insights for the smart design and preparation of inexpensive and high-efficiency photocatalytic materials. (C) 2017 Elsevier B.V. All rights reserved.