Electrochemical Cathodic Treatment of Mild Steel as a Host for Ni(OH)₂ Catalyst for Oxygen Evolution Reaction in Alkaline Media

Abstract

Abstract Oxygen evolution reaction (OER) catalysts and substrates play a vital role in the electrochemical water splitting process to generate chemical fuel and store renewable energy. The design and development of cost effective and efficient catalysts and substrates is still crucial and progressive towards the commercialization of water electrolyser. Herein, we have shown abundant mild steel (MS) as an efficient substrate as well as a catalyst host for OER by the cathodic treatment followed by the electrodeposited Ni(OH) 2 at room temperature. The C MS Ni(OH) 2 shows an overpotential ( η ) of 267 mV at a current density of 10 mA cm −2 with a Tafel slope of 66 mV dec −1 , and affordable stability at the benchmark scale of 10 mA cm −2 current density operation for 10 h and harsh condition of 100 mA cm −2 current density for 50 h in the continuous electrolysis chronoamperometry test in 1 M KOH. The higher catalytic activity of C MS Ni(OH) 2 compared to Ni(OH) 2 electrodeposited on MS is due to the interaction of Fe(OH) 2 /FeOOH and Ni(OH) 2 /NiOOH. These results suggest a possible way to utilize MS substrates as catalyst and as a host for OER and other electrochemical applications in the future.