Amorphous Iron and Cobalt Based Phosphate Nanosheets Supported on Nickel Foam as Superior Catalysts for Hydrogen Evolution Reaction

Amorphous iron and cobalt based phosphate catalysts supported on nickel foam were developed using the colloidal chemical method and evaluated for the hydrogen evolution reaction (HER). By using a catalyst with a specific ratio of Fe_0.72Co_0.42PO₄/Ni foam, an ultralow overpotential of 77 mV at a current density of 10 mA cm^–2 was achieved, which is even comparable to the noble platinum (Pt) catalyst. The promotion was verified with electrochemical impedance spectroscopy (EIS) and mainly attributed to the activation effect of Fe, which accelerates the charge transfer efficiency of Co to the benefit of catalyzing the reduction reaction of the hydrogen ions.