One-step assembly of 2H-1T MoS:Cu/reduced graphene oxide nanosheets for highly efficient hydrogen evolution.

The transition metal dichagenides and their metallic 1T structure are attracting contemporary attentions for applications in high-performance devices because their peculiar optical and electrical properties. The single and few layers 1T structure is generally obtained by mechanical or chemical exfoliation. This work presents facile one-step synthesis of 2H-1T MoS:Cu/reduced graphene oxide nanosheets. The experiment results indicated that the MoS and MoS:Cu prepared by simple chemical solution reaction possessed 2H-1T structures. The reduced graphene oxide (rGO) incorporation further induced the phase transition from 2H-MoS to 1T-MoS and morphology transition from granular/nanosheet to more nanosheet. The 2H-1T structure and 2H → 1T phase transition, together with the Cu doping and interface effect between the MoS and rGO, remarkably enhanced the conduction and photoconduction of the nanostructures. Thus, Cu doping and rGO incorporation obviously enhanced the catalytic activity and its stability, making the MoS:Cu/rGO nanosheet a most active and stable catalyst for hydrogen evolution. This work clearly indicates that the 1T-MoS nanosheets with high catalytic activity for hydrogen evolution can be easily obtained by the facile low temperature chemical method and induction of rGO.