RGO/sAC composites as electrode materials for supercapacitors to enhance electrochemical performance

Abstract

A compact composite of reduced graphene oxide (RGO) and spherical activated carbon (sAC) was prepared by microwave irradiation reduction using water as the solvent after mixing RGO and sAC and is a promising electrode material for supercapacitors. The removal of the oxygen functional group in RGO and the distinct structure of compact RGO/sAC composites are confirmed by FT-IR, XRD and XPS analyses. The morphology of the composite exhibits homogeneous and thick coating with an RGO nanosheet on the surface of the sAC. This structure has high micropore volume and leads to enhanced electrochemical performance. Based on the specific capacitance from the cyclic voltammetry curves, while the physical mixing compound of RGO/sAC (PM-RGO/sAC) is only 120 F/g at a scan rate of 2 mV/s, the compact RGO/sAC compound (MI-RGO/sAC) is 166 F/g by microwave irradiation, which enhances the specific capacitance by approximately 138% compared to that of the PM-RGO/sAC. Therefore, the composite material of MI-RGO/sAC driven by microwave irradiation can facilitate fast ion transport in supercapacitors and is a good candidate for electrodes.