Electrochemically Activated NiFeOxHy for Enhanced Oxygen Evolution

To minimize the utilization of fossil fuels, the demand for H 2 production through water electrolysis has considerably increased. NiFeO x H y -based electrocatalysts have attracted extensive attention owing to their excellent electrocatalytic activity in the oxygen evolution reaction (OER). To realize their commercialization, NiFeO x H y -based catalysts are being ameliorated for better performance in the OER. Here, we present a simple and scalable approach for fabricating NiFeO x H y by preparing a Ni–Fe master alloy plate followed by electrochemical activation including cyclized oxidation and reduction of metal ions. During the activation, the amorphous layer evolved only on the catalyst surface by circulating the oxidation states of Ni and Fe. The activated NiFeO x H y required only 250 mV of overpotential for 10 mA cm –2 and 30 mV dec –1 of Tafel slope, which is much better than the …