Metal Ni is a plentiful resource that can actively split water toward hydrogen evolution reaction (HER) in alkaline solution, but exploiting high-efficiency Ni-based composite catalysts is still a significant assignment. Therefore, we design a catalytic material with one-step approach to co-electrodeposit Ni nanoparticles and reduced graphene oxide (rGO) sheets on a three-dimensional Ni foam. When the carbon content existed in Ni-rGO composite catalyst is 3.335 at, the catalyst exhibits excellent activity on HER with a low Tafel slope (b = 77 mV dec(-1)), a high exchange current density (j(0) = 3.408 mA cm(-2)), small overpotentials of only 36,129, and 183 mV to drive 10, 60, and 100 mA cm(-2) respectively, and high stability under the different current densities. Such remarkable hydrogen evolution performance is attributed to good electrical conductivity, large specific surface area and harmonious synergistic effect between Ni particles and rGO sheets. In addition, density functional theory (DFI) calculations explain that Ni-rGO composite material presents superior interfacial activity in adsorption/desorption of H* compared with pure Ni and rGO sheet. (C) 2017 Elsevier B.V. All rights reserved.