Cu doped MoS2 (Cu-MoS2)/reduced graphene oxide (rGO) (Cu-MoS2/rGO) hybrid material is fabricated by a facile one-step solvothermal method. The X-ray diffraction (XRD) results suggest that the doping of Cu does not alter the crystal structure of MoS2. X-ray photoelectron spectroscopy (XPS) analysis reveal that the doping of Cu atoms influences the electronic structure of MoS2, which is favorable to increase active sites of edges. Electrochemical impedance spectroscopy (EIS) results indicate that Cu-MoS2/rGO performed a faster charge-transfer in comparison to MoS2/rGO hybrid. In addition, the resultant Cu -MoS2/rGO catalyst with Cu/Mo mole ratio of 9% exhibits a lower overpotential of 199 mV at 10 mA cm(-2), small Tafel slop of 44 mV dec(-1) and cycling stability, indicative of enhanced electrocatalytic activity towards HER. The improved performance is attributed to the increased active sites and a synergistic effect between copper and molybdenum, leading to electronic structure change and charge redistribution of MoS2. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.