Synthesis, Characterization and Electrochemical Study of Graphene Oxide-Multi Walled Carbon Nanotube-Manganese Oxide-Polyaniline Electrode as Supercapacitor

The synthesis of graphene oxide-multi walled carbon nanotube-manganese oxide-polyaniline namely (GMMP) nanocomposite for application in supercapacitor devices was investigated. Morphology of the nanocomposites was studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray microanalysis (EDX). The electrochemical properties of nanocomposite based electrodes were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS) techniques in 0.5 mol/L Na2SO4. The specific capacitances of 173.00, 127.85, 87.50, 58.65 and 12.00 (mF cm−2) were obtained for GMMP, GMP (GO–MWCNT–PANI), GMM (GO–MWCNT–MnO2), GM (GO–MWCNT) and G (GO) at a scan rate of 10 mV s−1, respectively. Also, GMMP nanocomposite retained 90% initial capacitance after 200 cycle of charge–discharge. The good electrochemical response of this nanocomposite is due to the combination of the electrical double layer capacitance of GO and MWCNT and the gradual introduction of pseudo-capacitance through the redox processes of PANI, –COOH, –OH (in MWCNT–COOH, GO–COOH and GO–OH) and MnO2. This revealed the synergistic effect of PANI, MnO2, –OH –COOH on the carbon based support.