Electrochemical preparation and alkaline water splitting activity of ternary Co–Fe–Mo non-crystalline coatings.

The influence of Na 2 MoO 4 concentration on the electrochemical deposition of Co–Fe and Co–Fe–Mo alloy coatings from slightly acidic citrate baths and their electrocatalytic performance for alkaline water electrolysis in 1 M NaOH solution have been examined. The chemical composition and the evolution of the crystallographic structure have been analyzed by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) measurements. Increasing concentration of Mo in the alloy led to gradual amorphization of the crystalline structure. Electrochemical studies revealed that the cathodic Tafel slope reduced to 69 mV/dec for Co–Fe–Mo alloys. Furthermore, a low overpotential value of −121 mV was observed from polarization studies, which confirmed a good catalytic activity for the alkaline water splitting process. • Co–Fe and as Co–Fe–Mo ternary alloys, were fabricated on a copper electrode at different conditions. • Addition of Mo into alloy led to amorphization of the crystalline structure and decrease the overpotential value. • The enhanced activity of Co 57 Fe 24 Mo 19 ternary alloy is related to the synergetic effects between elements. [ABSTRACT FROM AUTHOR]