Investigation of electrochemical behavior of Co3O4–Mn2O3/rGO nanocomposite for supercapacitor applications

Metal oxides exhibit high theoretical specific capacitance due to its multiple oxidation states and when combined with reduced graphene oxide (rGO) may produce synergistic effects. Hence various metal oxides with rGO have been studied for supercapacitor properties. In this work, a two-step hydrothermal approach was followed to produce Co3O4 – Mn2O3 / rGO nanocomposite with the average crystallite size of 14 nm. Functional groups in the rGO allow for the nucleation to occur on its surface which results in the successful metal oxide nanocomposite formation. The formed metal oxides has average particle diameter of 29 nm with surface area of 14.139 m2/g. Mesoporous nature of the nanocomposite was obtained with an average pore diameter below 20 nm. The presence of more active sites for the electrolyte ions in the electrode surface results in higher specific capacitance of 663 F/g at 1 A/g and low electrode resistance of 0.39 Ω. Thus the electrochemical studies reveal the diffusion controlled intercalation process over a potential range of 0–0.6 V.