环境材料与生态化学研究发展中心知识库

The graphene-MnO₂-polyaniline (rGO-MnO₂-PAn) ternary composites were prepared via in situ chemical oxidative polymerization of polyaniline on the MnO₂ decorated graphene sheets. The graphene sheets were treated with KMnO₄ in a water-ethylene glycol system using the hydrothermal method to complete the loading of MnO₂ on the graphene sheets, while the graphene oxide (GO) sheets were hydrothermally reduced to reduced graphene oxide (rGO). The glycol was introduced as a reductant to react with MnO₄, and GO was protected from consumption in the process of deposition of MnO₂. The structures and morphologies of the resulting ternary composites are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the composites as potential electrode materials for supercapacitors were investigated using different electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS). The specific capacitance of a rGO-MnO₂-PAn composite electrode was 395 F g^-1 at 10 mA cm^-2 in 1 M H₂SO₄ solution. The composites displayed good cycle stability retaining 92% of their original specific capacitance after 1200 cycles by continuous cyclic voltammetric scans at 100 mV s^-1.