Perovskite-type samarium iron oxide adorned on reduced graphene oxide composite: A high-performance electrocatalyst for OER

Abstract

The oxygen evolution process (OER), an essential and necessary reaction in water splitting to produce clean hydrogen fuel were investigated using a number of electrocatalysts. Non-noble metal catalysts are increasingly being used in place of noble metal catalysts because of their unique qualities, which include affordability, environmental friendliness and electrocatalytic activity. In this work, SmFeO3/rGO composite is prepared for an anion exchange reaction, which is used as catalyst on nickel foam in 1.00 M KOH electrolyte for OER. The fabricated electrocatalysts were confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM). The BET determined surface area of SmFeO3/rGO composite is 51 cm2/g which is better for OER activity. The distinct structure of the nanocomposite displays increased surface area, increasing active sites with plentiful potential for charge transfer and prolonging the material's life. The electrochemical results represented that composite had lower overpotential (180 mV) with Tafel slope (34 mV/dec), displaying higher charge transfer during OER showing efficient electrocatalytic activity and high reliability of 55h. The reasons for lower overpotential and lower Tafel slope values were increased surface area and enhanced number of active spots in composite and also due to presence of non-kinetic effects that alter the Tafel slope values. The electrocatalyst may be able to facilitate the oxidation reaction based on all of these qualities. As a consequence, created composite reacts with outstanding efficacy for the OER process and energy conversion applications.