▎ 摘　　要

Electrochemical water splitting has become a potential pathway for sustainable hydrogen production, where high-efficiency low-cost catalysts are highly desirable. MoS2 is a promising candidate to substitute effective but expensive Pt-based catalysts for hydrogen evolution reaction. In this work, the computer simulation results reveal that alloying with Co and compositing with graphene could significantly improve the electrocatalytic performance of MoS2 thanks to the activation of MoS2 inert surfaces and enhanced electron transport. Based on this finding, we designed and synthesized a catalyst of (CoMo)S-2/graphene, which exhibits excellent performance with low onset potential (28 mV), overpotential (100 mV) for driving a current density of 10 mA cm(-2), and Tafel slope (60.8 mV dec(-1)), superior to most of MoS2-based electrocatalysts reported in open literatures. This study supplies important information for fundamental understanding of high-efficiency non-noble electrocatalysts toward applications in energy-conversion devices.