Structural and Electrochemical Properties of NiFe2-xCuxO4 Spinel for Oxygen Evolution Reaction

Abstract

Developing new material oxides catalysts for the oxygen evolution reaction in alkaline media is important to enhance the efficiency of the water-splitting process. For this purpose, the effect of copper doping on the structural, morphological, and catalytic properties of NiFe2CuO4 oxides for the oxygen evolution reaction has been investigated. X-ray diffraction analysis of samples calcined at 1000 °C shows that the pure spinel structure was obtained in the range 0 ≤ x ≤ 0.4. The FTIR spectra confirm the presence of the metal-oxygen bond of M-O in the tetrahedral and octahedral sites of the spinel structure. Scanning electron microscopy (SEM) shows that the calcined powders have a compact and dense surface and pronounced agglomeration. The OER results indicate that the NiFe2O4 electrode exhibits a higher performance with the current density of 26 mA.cm−2 at 0.55 V and a small Tafel plot of 68 mV.dec−1. Further investigations also accounted for the degradation of electrocatalytic activity with increasing copper content.