Nanostructured Ni-Co alloys decorated on 3D porous nickel electrodes for hydrogen evolution reaction (HER) are successfully prepared through a facile and effective electrodeposition method. By adjusting the current density of electrodeposition, Ni-Co alloys with different surface morphologies like nanocones, leaf-like structures and flakes can be obtained. The HER catalytic activity has been greatly reinforced with decorated Ni-Co alloys. Meanwhile, the HER performance of nanocone Ni-Co alloys outperforms that of leaflike and flaky Ni-Co alloys. The nanocone Ni-Co alloys exhibit outstanding HER activity, only requiring an overpotential of 86.7 mV at 10 mA cm(-2), along with a low Tafel slope of 69.8 mV dec(-1) and 3.4 Omega charge transfer resistance. This nanocone electrode remains stable for 10 h of chronopotentiometric measurement. Such enhanced catalytic performance stems from the porosity and the high population of sharp edges, as well as surface oxidation/metallic states and synergistic effects between Ni and Co. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.