Interface coupling of 1T-phase dominated MoS nanosheets with nitrogen-doped graphene towards enhanced hydrogen evolution reaction

Abstract

• 1T-MoS x nanosheets vertically grown on N-doped graphene via interface coupling strategy. • Mo–N coupling hetero-interface promotes 2H-to-1T phase transition of MoS x. • Interface structure and phase composition optimized by tuning N-doped graphene content. • Enhanced hydrogen evolution reaction activity and excellent cycling stability achieved. Herein, a three-dimensional network hetero-structure comprising 1T-phase dominated MoS x nanosheets vertically grown on nitrogen-doped reduced graphene oxide (MoS x /N-rGO) was constructed through a surfactant-free hydrothermal route and applied to hydrogen evolution reaction (HER). We demonstrate that N species in graphene lattices play a vital role for the interface coupling between MoS x and N-rGO via Mo–N bonds, thereby promoting the 2H-to-1T phase transition of MoS x . By adjusting N-rGO content, the 1T-phase concentration of MoS x can reach 81.7% and the corresponding surface structure is optimized. The excellent synergistic effect dependent on robust hetero-interface can increase basal plane/edge active sites and accelerate electron/proton reaction kinetics. Consequently, MoS x /N-rGO exhibits enhanced HER activity with a low onset potential of 100 mV, notably small Tafel slope of 38 mV dec −1 and excellent cycling stability.