▎ 摘　　要

In this study, a simple and one-step cost-effective preparation of rGO/Co3O4 nanocomposite was given out in different monomer concentrations of [rGO]o/[Co3O4]o= 1:1; 1:2; 1:5 and 1:10. The electroactive materials were characterized by many techniques, such as FTIR-ATR, XPS, TGA-DTA, Raman, BET surface analysis, GCD, SEM-EDX, XRD, TEM, CV, and EIS analysis. A symmetric supercapacitor applying rGO/Co3O4 nanocomposite as positive and negative electrodes was taken in the potential window between 0.0 and 0.8 V as the highest specific capacitance of Csp= 115.35 Fxg-1 at 2 mVxs-1 for [rGO]o/[Co3O4]o= 1:2. Furthermore, the highest energy (E) and power densities (P) were obtained as E= 20.16 Whxkg-1 at 40 mA and P= 26.140 kWxkg-1 at 10 mA for [rGO]o/[Co3O4]o= 1:2 by GCD method, respectively. As a result, rGO/Co3O4 nanocomposite at different monomer concentrations showed an easy synthesis, a sustainable approach, and a high electrochemical performances for energy storage devices.