Effect of metal ion substitution on electrochemical properties of cobalt oxide

Abstract 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 MnCo 2 O 4 , FeCo 2 O 4 , Co 3 O 4 , NiCo 2 O 4 , CuCo 2 O 4, and ZnCo 2 O 4 , were synthesized using a hydrothermal method. The effects of metal ion substitution on the electrochemical properties of Co 3 O 4 for energy storage applications were studied. The synthesized FeCo 2 O 4 electrodes showed a maximum specific capacitance of 1319 F/g at 1 mV/s. Supercapacitor device was fabricated using FeCo 2 O 4 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 °C. Furthermore, FeCo 2 O 4 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.