Reduced graphene oxide as an efficient support for CdS-MoS2 heterostructures for enhanced photocatalytic H2 evolution

Cadmium sulphide nanorods-reduced graphene oxide-molybdenum sulphide(CdS-rGO-MoS₂) composites were successfully synthesized using hydrothermal process for enhancing the interfacial contact between CdS nanorods and MoS₂ layer. The good contact between CdS and MoS₂ is important for improving the photocatalytic hydrogen (H₂) evolution. The morphological and structural studies showed the production of highly pure CdS phase with nanorod-like structure dispersed on rGO-MoS₂ layer. X-ray photoelectron spectroscopy (XPS) and Raman results confirmed the reduction of graphene oxide (GO) into reduced graphene oxide (rGO). The higher photocurrent density of CdS-rGO-MoS₂ composites compared to CdS/MoS₂ and the fluorescence quenching observed for this composite provided some evidence for an inhibition of electron-hole recombination, which leads to a longer life time of the photogenerated carriers. Fast electron transfer can occur from CdS nanorods by the bidimensionnel rGO area to MoS₂ layer due to the intimate interfacial contact. Composite CdS-rGO-MoS₂ with 20 wt% rGO was found to be the most effective photocatalyst for H₂ evolution (7.1 mmol h^?1g^?1). The good photocatalytic performance arose from the positive synergistic effect between CdS, rGO and MoS₂ elements.