Her activity of nickel coated graphite electrodes doped with CoW and CoIr nanoparticles

In this study, hydrogen evolution reaction (HER) was studied on CoW and CoIr nanoparticles deposited on the Ni plated graphite electrodes (C/NiCoW and C/NiCoIr) and their catalytic activities were determined. Nanoparticles were synthesized hydrothermally and HER activity of the prepared electrodes was investigated by electrochemical techniques. Electrochemical analyses were carried out by the potentiodynamic polarization technique and electrochemical impedance spectroscopy. Cyclic Voltammetry was used to characterize deposited catalysts and voltammograms showed successful deposition. With the use of scanning electron microscopy, and energy dispersive X-ray spectroscopy techniques, Surface morphology and chemical composition of synthesized nanoparticles were examined. It was determined that HER efficacies of C/NiCoW and C/NiCoIr catalyst in 1.0 M KOH solution was higher than C/Ni catalyst and the cathodic Tafel constant values were 177 mV dec-1, 187 mV dec-1 and 191 mV dec-1 for C/NiCoW, C/NiCoIr and C/Ni respectively. The hydrogen volume was measured by electrolysis for 3 V over 30 min with C/NiCoW producing highest volume of 54 mL cm-2 followed by C/NiCoIr with 52.5 mL cm-2 and C/Ni, 49.8 mL cm-2.