One-step green route synthesis of spinel ZnMn2O4 nanoparticles decorated on MWCNTs as a novel electrode material for supercapacitor

This work focuses on designing new electrode materials by fabricating a nanocomposite hybrid of MWCNTs and a binary metal oxide, ZnMn2O4. The ZnMn2O4 has been extensively investigated as a high-performance anode in Li-ion battery, however, its capacitive faradaic charge storage behavior is rarely explored. Herein we demonstrate the fabrication of ZnMn2O4-CNT nanocomposites using acid modified MWCNTs and a one-step green hydrothermal method for supercapacitor application. The SEM analysis of the as-fabricated composites showed that the ZnMn2O4 nanoparticles were uniformly anchored on the MWCNTs backbone, which helps to maintain good electrical channel throughout the composite. Electrochemical characterizations were carried out in a three-electrode configuration in the 1 M Na2SO4 electrolyte in terms of cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy analyses. The synergistic interaction between the MWCNTs and the ZnMn2O4 nanoparticles resulted in a high specific capacitance of 103 F/g of the as-fabricated electrode.