Effect of Gd2O3 on the hydrogen evolution property of nickel–cobalt coatings electrodeposited on titanium substrate

The effect of rare earth compound, Gd2O3, on the microstructure and the hydrogen evolution property of Ni–Co alloy electrode was studied. The morphology and microstructure were characterized by SEM and XRD, respectively, and the electrocatalytic efficiency was evaluated on the basis of electrochemical data obtained from steady-state polarization curves, Tafel curves and electrochemical impedance spectroscopy measurements carried out in 0.50 M Na2SO4+0.10 M H2SO4 solution. It was found that the embedded Gd2O3 particles largely enhanced the electrocatalytic activity of Ni–Co alloy electrode to hydrogen evolution reaction.

► Pronounced electrochemical performance of Ni–Co/Gd2O3 composite electrode for HER. ► Higher electrocatalytic activity of the composite electrode based on increased real surface area. ► Overpotential decrease of about 130 mV at 9.0 mA cm−2 compared with that of Ni–Co electrode. ► Real exchange current density of hydrogen evolution kinetics enhanced 2.07 times.