Effect of metal ion substitution on electrochemical properties of cobalt oxide

Metal oxides are being used for various applications such as batteries, supercapacitors, and catalysts due to notable electrochemical properties, multifunctional applicability for energy applications, and low cost. In this work, different metal oxides such as MnCo2O4, FeCo2O4, Co3O4, NiCo2O4, CuCo2O4, and ZnCo2O4, were synthesized using a hydrothermal method. The effects of metal ion substitution on the electrochemical properties of Co3O4 for energy storage applications were studied. The synthesized FeCo2O4 electrodes showed a maximum specific capacitance of 1319 F/g at 1 mV/s. Supercapacitor device was fabricated using FeCo2O4 electrodes, which showed improvement in energy storage capacity with an increase in temperature. An over 100% improvement in charge storage capacity was reached when the temperature increases from 10 to 60 degrees C. Furthermore, FeCo2O4 electrodes were studied as energy generation in oxygen evolution reaction (OER). These electrodes showed promising electrocatalytic activity with a low overpotential of 308 mV at 10 A/g. Our results suggest that the electrochemical properties of metal oxides can be tuned and used as advanced materials for energy applications. (c) 2018 Elsevier B.V. All rights reserved.