Electrochemical Oxygen Evolution Reaction on NixFe3-xO4 (0 ≤ x ≤ 1.0) in Alkaline Medium at 25ºC

Spinel ferrites (NixFe3-xO4; x = 0.25, 0.5, 0.75 and 1.0) have been prepared at 550ºC by egg white auto-combustion route using characterized physicochemical (TGA, IR, XRD, SEM) electrochemical (CV Tafel polarization) techniques. The presence of characteristic vibration peaks in FT-IR reflection planes XRD spectra confirmed the formation spinel ferrites. oxides were transformed into oxide film on glassy carbon electrodes coating powder ink nafion solution investigated their electrocatalytic performance for OER an alkaline solution. cyclic voltammograms electrode did not show any redox oxygen overpotential regions. iR-free polarization curves exhibited two slopes (b1 59–90 mV decade−1 b2 92–124 decade−1) lower higher over potential regions, respectively. Ni-substitution matrix significantly improved activity evolution reaction. Based current density OER, mol Ni-substituted was found to be most active among showed highest value apparent (~9 mA cm−2 0.85 V) lowest slope (59 decade−1). occurred via chemisorbed intermediate sites follow second-order mechanism.