Ni/NiFe2O4 Composite Electrode Prepared by Electro-deposition and Its Electro-catalytic Performance Towards Oxygen Evolution Reaction

Abstract

The spinel-type NiFe2O4 powders have been synthesized by a hydroxide co-precipitation method.The Ni/NiFe2O4 composite coating was prepared through electro-deposition in Watt nickel plating by adding some NiFe2O4 powders.The optimized plating conditions for the composite electro-deposition were investigated by varying parameters,such as the plating solution pH and the cathode current density jk.The composition and structure of the Ni/NiFe2O4 composite coating were characterized by scanning electron microscopy(SEM),energy X-ray diffraction(XRD) and dispersive spectrometer(EDS).The results show that the NiFe2O4 mass content in the Ni/NiFe2O4 composite coating is the highest(55.15%) at optimized plating conditions of a solution pH = 5.8 ～ 6.0 and a cathodic current density jk = 40 × 10-3 ～ 60 × 10-3 A/cm2.In 5 mol/L KOH solution,the electro-catalytic properties towards the oxygen evolution reaction(OER) of the Ni/NiFe2O4 composite electrode was studied using cyclic voltammetry,steady-state polarization,and chronoamperometry.Compared with the nickel electrode,the electro-catalytic properties towards OER of the Ni/NiFe2O4 electrode is higher and the apparent activation energy is decreased by 62.07 kJ/mol,and its specific surface area is 23.02 times as large as that of the nickel electrode.The constant-potential electrolysis with long time for OER shows that the stability of the Ni/NiFe2O4 composite electrode is good.