Nanosized γ-MnO2/Graphene aerogels composites and their supercapacitive properties

• 1、Department of Environmental Science and Engineering, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
• 2、School of Chemical, Xiangtan University, Xiangtan 411105, China

Abstract：Graphene aerogels were prepared by microwave digestion through reducing graphene oxide. Graphene aerogels,which have three-dimentional porous network structure, were then used as the substrate for loading γ-MnO2 by liquid deposition.The prepared Nanosized γ-MnO2 /Graphene aerogels composites were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), thermogravimetry analysis. The electrochemical performance of the composites were investigated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy in 6 mol L-1 KOH electrolyte. Results show that the content of nanosized γ-MnO2 in nanosized γ-MnO2/Graphene aerogels composites were about 25 wt.%. The specific capacitance of the composite is as high as 328.0 F g-1 at a scan rate of 2 mV s-1, which was increased 60.9% than the graphene aerogels (203.9 F/g) by microwave digestion.

Keywords： Physical chemistry； γ-MnO2 ；graphene；supercapactior