Electrocatalytic properties for the hydrogen evolution of the electrodeposited Ni-Mo/WC composites

The catalytical activity for the hydrogen evolution reaction (HER) of the electrodeposited Ni -Mo/WC composites is examined in 1 M KOH solution. The structure, surface morphology and surface composition is investigated using the scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The electrocatalytic properties for the HER is evaluated based on the cathodic polarization, electrochemical impedance, cyclic voltammetry and chronopotentiometry methods. The obtained results prove the superior catalytic activity for the HER of Ni-Mo/WC composites to Ni-Mo alloy. The catalytic activity of Ni-Mo/WC electrodes is determined by the presence of WC nanoparticles and Mo content in the metallic matrix. The best electrocatalytic properties are identified for Ni -Mo/WC composite with the highest Mo content and the most oxidized surface among the studied coatings. The impedance results reveal that the observed improvement in the catalytic activity is the consequence of high real surface area and high intrinsic catalytic activity of the composite. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The catalytic activity for hydrogen evolution reaction of electrodeposited Ni-Mo/WC composites in 1 M KOH solution is investigated, showing superior performance compared to Ni-Mo alloy. The presence of WC nanoparticles and Mo content in the metallic matrix significantly affect the electrocatalytic properties. The best performance is observed in the composite with the highest Mo content and most oxidized surface.