Production and characterization of high-performance cobalt–nickel selenide catalyst with excellent activity in HER

Designing of complex nanostructure with a high specific surface area using transition metal selenide seems to be a necessity in response to the challenges of the hydrogen release process for renewable energy. Herein, we synthesized the electrocatalyst nickel foam-supported with nanostructured nickel–cobalt selenide using the hydrothermal process at 150 and 180 °C and has been investigated in hydrogen evolution reaction. Synthesis of nickel–cobalt selenide nanostructure on nickel foam carried out with different Ni +2 :Co +2 mol ratios of 0:10, 2:8, 6:4, 4:6, 8:2, and 10:0 in the structure of electrodes. The XRD results indicate the formation of the nickel–cobalt selenide phase in different ratios. The FESEM and TEM results show the formation of mesoporous three-dimensional nano-lactic with petal thickness in the range of 20–30 nm. Also, to evaluate the properties and electrocatalytic efficiency, electrochemical tests of Tafel slope, cyclic voltammetry, linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) were used. The Tafel result test shows a cathodic slope of −61.3 mV and an exchange current density of 0.86 mA cm −2 in the Ni 8 Co 2 Se-150 (Ni +2 :Co +2 = 8:2) sample, which LSV shows −185 mV at a current density of −10 mA cm −2 . EIS test shows a polarization resistance value of 2744 Ω for mentioned sample and was selected as the best sample with the highest catalytic activity.