Three-dimensionally hierarchical MoS2/graphene architecture for high-performance hydrogen evolution reaction

Abstract Molybdenum disulfide(MoS 2 ) has been considered as a potential alternative to precious metalcatalysts for the hydrogen evolution reaction (HER). However, the performance of MoS 2 is still limited due to the poor electron conductivity, scarce active sites and low structural stability. A multiscale design of MoS 2 in the structure and atomic composition is needed but still a great challenge. Herein, we report a well-organized three-dimensionally (3D) mesoporous hybrid structure of Co-doped MoS 2 and graphene for highly efficient electrocatalytic HER. The mesoporous morphology ensures the well-dispersion of MoS 2 layers and exposure of abundant edge sites. Doping of Co atoms into the MoS 2 lattice improves the intrinsic HER activity of in-plane sulfur sites. The highly conductive and robust graphene network enhances the conduction of electrons and simultaneously improves the stability of the hybrid structure. The catalyst achieves a current density of 10 mA cm −2 at an overpotential of 143 mV versus the reversible hydrogen electrode(RHE) which is 200 mV lower compared with pure 2D MoS 2 , and maintains the activity for over 5000 cyclic voltammetry sweeps. This work provides a promising strategy for efficiently enhancing both the activity and stability of MoS 2 -based catalyst for HER.