In-situ grown nickel-cobalt bimetallic nanowire arrays for efficient hydrogen evolution reaction

Nickel-based nanowire arrays with different cobalt content were prepared via a modified template-assisted electrodeposition method for hydrogen evolution reaction. The experimental results proved that, compared with samples of other ratios, the nanowire arrays with a nickel-cobalt atomic ratio of 32:1 exhibited better hydrogen evolution performance, and an overpotential of 103 mV was required to obtain a current density of 10mAcm−2, while the nanowire arrays with a ratio of nickel-cobalt of 3:1 required an overpotential of 171 mV to achieve the same current density. The density functional theory (DFT) calculations performed were consistent with the experimental results that Ni-based materials doped with 1Co had better electrocatalytic activity than those doped with 2Co. The excellent hydrogen evolution performance of catalyst was attributed to the synergy between nickel and cobalt atoms and the nanowire structure increased the specific surface area exposing more active sites for hydrogen adsorption and adsorption.