Electrodeposition of Fe-Co-Ni coating by cyclic voltammetry for efficient hydrogen production

Self-supported nanostructures of Fe-Co-Ni were synthesized on Cu foam (CuF) through a single-step cyclic voltammetry electrodeposition (CVED) technique under various coating conditions. A comprehensive analysis examined the influence of electrodeposition parameters, including Potential Scan Rate (PSR) and Number of Coating Cycles (NCCs). The findings revealed that the coating generated at lower PSR possessed higher Fe, Co and Ni contents (Fe: 26.77 %, Co: 42.02 %, and Ni: 31.21 %) and displayed enhanced efficacy for hydrogen evolution reaction (HER), manifesting overpotentials of -65, -94, and -214 mV vs. reversible hydrogen electrode (RHE) for the current densities of -10, -20, and -100 mA/cm2, respectively. Additionally, the acceptable electrochemical stability of the electrode was substantiated via chronopotentiometry. The ICP-OES, XPS, and EIS techniques were employed to delve deeper into the stability, and it was ascertained that the formation of a passive layer on the surface of the electrocatalyst after cathodic polarization was accountable for its resistance to degradation. In contrast, no association was found between film thickness and corrosion resistance.