Synthesis, characterization, and supercapacitor performances of activated and inactivated rGO/MnO2 and rGO/MnO2/PPy nanocomposites

Abstract

In this study, a ternary nanocomposite of reduced graphene oxide (rGO), manganese dioxide (MnO2), and polypyrrole (PPy) was synthesized and characterized and presented electrochemical performances of supercapacitor devices. Four types of activated and inactivated materials (rGO/MnO2, rGO/MnO2*, rGO/MnO2/PPy, and rGO/MnO2*/PPy) were investigated by Fourier transform infrared-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersion X-ray analysis (SEM-EDX), Raman spectroscopy, Brunauer-Emmett-Teller (BET) surface analysis, thermogravimetric (TGA-DTA) analysis, cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) analysis. Synthesis procedures are easy and low cost and have good conductivity performances compared with other methods. Activated MnO2* and inactivated MnO2 were used in the nanocomposite system. The highest specific capacitance was obtained as Csp = 348.11 F/g at 0.5 mA for rGO/MnO2* nanocomposite by GCD method. The spectroscopic, morphologic, pore size, thermogravimetric, and electrochemical differences of activated and inactivated MnO2 materials are presented in this manuscript. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.