One-Step Electrofabrication of Reduced Graphene Oxide/Poly( N -methylthionine) Composite Film for High Performance Supercapacitors

Graphene based conducting polymer composites have demonstrated remarkable potential in supercapacitors. Here we develop a facile one-step cyclic voltammetric codeposition method for the fabrication of a reduced graphene oxide (rGO)/conducting redox polymer composite film on a graphite paper (GP) substrate using graphene oxide (GO) and a redox dye N -methylthionine (NMTh) as precursors. The morphology, composition, and structure of the composite film were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The resulting composite film has a layered and encapsulated microstructure, large specific area, high electrical conductivity, and fast reversible redox activity. The as-prepared rGO/polymeric redox dye composite film shows high specific capacitances of 500 and 400 F g ^–1 at 0.5 and 10 A g ^–1 current densities, respectively, with a retention life of up to 93.0% over 1000 charge/discharge cycles at 0.5 A g ^–1 . This coelectrodeposition may provide a promising method for the fabrication of graphene/other conducting redox polymer composites for energy storage application.