Fabrication of rGO/CdS@2H, 1T, amorphous MoS2 heterostructure for enhanced photocatalytic and electrocatalytic activity

Abstract

The synthesis of high efficiency noble metal free catalysts is an important target for H2 production by water-splitting. In this work, rGO/CdS@MoS2 heterostructure with two catalytic paths was successfully synthesized and as the first applied the heterostructure in the field of electrocatalysis. The MoS2 structure is adjusted by controlling hydrothermal process. Moreover, the effects of structure and loading amount of 2H–MoS2, 1T-MoS2 and amorphous MoS2 (A-MoS2) on catalytic performance were also studied. The catalytic activity of rGO/CdS@MoS2 heterostructure has been improved obviously. Compared with 2H–MoS2, the distortion of 1T-MoS2 and the defect of A-MoS2 make it have more unsaturated S, so rGO/CdS@1T-MoS2 and rGO/CdS@A-MoS2 have better catalytic activity. For photocatalytic H2 evolution, loading MoS2 and rGO on catalysts changes the energy band structure, promotes the separation of electron-holes and provides a large number of active sites. Among them, the visible light photocatalytic H2 production rate of rGO/CdS@1T-MoS2 with 0.1 mol of 1T-MoS2 (CT0.1-G1) is 18.26 mmol/g/h. During the electrocatalytic H2 evolution, introducing MoS2 and rGO improves electronic structure and increases active sites. rGO/CdS@1T-MoS2 with 0.5 mol of 1T-MoS2 (CT0.5-G1) shows the low overpotential (312 mV) and Tafel slopes (85 mV/dec).