One-pot Hydrothermal Synthesis of 3D Flower-like RGO/Co3O4/Ni(OH)2 Composite Film on Nickel Foam for High-performance Supercapacitors

Abstract

Reduced graphene oxide (RGO)/Co3O4/Ni(OH)2 composites on nickel foam (NF) were hydrothermal-assisted synthesized by using a modified “active metal substrate” route, in which nickel foam acted as both a reductant of GO and Ni source, and a substrate for composite film. As-synthesized samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FESEM), and transmission electron microscopy (TEM). The electrochemical performances of the supercapacitor with the as-synthesized RGO/Co3O4/Ni(OH)2/NF electrodes are evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectrometry (EIS) in 1M KOH aqueous solution. It is found that the RGO/Co3O4/Ni(OH)2/NF electrode exhibits superior capacitive performance with high capability (10.24 F cm−2 at a current density of 11mAcm−2, i.e., 2133.3 F g−1 at 2.3 A g−1), compared with the Co3O4/Ni(OH)2/NF electrode (1.71 F cm−2) and the RGO/Ni(OH)2/NF electrode (0.95 F cm−2) prepared under identical conditions.