CoMoS2/rGO/C3N4 ternary heterojunctions catalysts with high photocatalytic activity and stability for hydrogen evolution under visible light irradiation

Noble metal free MoS 2 /g-C 3 N 4 catalyst has attracted intense attentions for visible light photocatalytic hydrogen evolution as a result of its earth abundance, low cost and unique heterojunctions stacked with two dimensional sheets. However, the low charge separation efficiency resulted from the poor conductivity of g-C 3 N 4 and MoS 2 , and lack of abundant active sites from coordinative unsaturated atoms in MoS 2 , restricts the photocatalytic hydrogen evolution activity and stability enhancement of MoS 2 /C 3 N 4 composite catalysts. Herein, CoMoS 2 /rGO/g-C 3 N 4 catalysts with ternary heterojunctions are prepared by facile solvothermal method, which exhibit high visible light photocatalytic activity and stability for hydrogen evolution. The optimal hydrogen evolution rate of CoMoS 2 /rGO/g-C 3 N 4 catalysts is 684 μmol g −1  h −1 when the content of CoMoS 2 is 2% and the content of rGO is 0.5%. The stability of CoMoS 2 /rGO/C 3 N 4 catalysts just decrease about 3% after 4 cycling runs for 16 h. The good catalytic performances of catalysts are attributed to the synergistic effect among the g-C 3 N 4 nanosheets, rGO nanosheets and CoMoS 2 nanosheets. The high conductivity of rGO nanosheets enhances the electron-hole separation and charge transfer, and Co doping increases the active sites for hydrogen evolution due to the increase of unsaturated atoms in CoMoS 2 nanosheets.