Porous hollow nanorod structured chromium-substituted inverse spinel compound: An efficient oxygen evolution reaction catalyst

Abstract

Spinel-based oxygen evolution reaction (OER) catalyst using various cation substitution strategies is gained importance due to its improved catalyst performance. Herein, we report the chromium (Cr)substituted nickel ferrite, inverse spinel compound (NiCrFeO4) of porous hollow nanostructure using a simple electrospinning approach. The developed inverse spinel compound displays a nanorod-shaped nanostructure of an overall diameter of 60 +/- 10 nm and an inner hollow thickness of 30 +/- 10 nm. In this study, the Cr-substituted catalyst delivers an overpotential value of 298 mV which is lower than the developed electrospun-based Cr-free NiFe2O4 (330 mV) and the commercial-based NiFe2O4 (330 mV) compound at 10 mA cm(-1) under 1 M KOH. Further, the Cr-substituted catalyst exhibits a low Tafel slope value of 44.7 mV dec(-1) than the RuO2 catalyst (63.7 mV dec(-1)). In addition, the catalyst is able to deliver excellent OER durability of 14 hrs at voltage retention of 94.5 % at 10 mA cm(-2) condition. In this study, a simple method and a favorable nanostructure to unveil a potential OER candidate are developed. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.