Producing hydrogen through a hydrogen evolution reaction (HER) by splitting water at the suitable overpotential is a great alteative to solving the problems of environmental pollution and the energy crisis.Molybdenum sulfide (MoS2)has attracted extensive attention as one of the most promising catalytic materials for HER.In this work,we design a facile method to in situ grow gold nanoparticles (AuNPs) on MoS2.Different numbers of AuNPs with MoS2are used to find the best catalytic activity.Due to the larger active surface area and higher conductivity of the Au-MoS2 composites,all the Au-MoS2 composites exhibit more enhanced HER electroactivity than pure MoS2.In brief,the new material architecture exhibits optimized HER activity with a low onset overpotential of 0.12 V,low Tafel slope of 0.163 V·dec-1,and an excellent stability in acidic solution.