▎ 摘　　要

In this study, Co3O4@NGO/polyindole composites were synthesized using ultrasonication followed by hydrothermal processes. The structure and morphology of composites were investigated by analytical techniques such as Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), X-ray photo electron spectroscopy (XPS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and BrunauerEmmettTeller (BET) surface analysis. The electrochemical performances of the composites were studied by cyclic voltammetry (CV), galvanostatic charge discharge (GCD)and electrochemical impedance spectroscopy analysis (EIS) measurements. As a proof of concept demonstration we have employed Co3O4@NGO/polyindole (PIN) as an electrode in supercapacitor. The Co3O4@NGO/PIN composite showed a capacitance of similar to 680 F g(-1) at 0.5 Ag-1 and had an excellent cycling stability of 96% after 5000 cycles at 0.5 Ag-1 indicating the material as a potential candidate in supercapacitor applications. (C) 2020 The Authors. Published by Elsevier B.V.