Active-screen plasma multi-functionalization of graphene oxide for supercapacitor application

Supercapacitors have attracted much attention as energy storage device for its long cycle life and high power density. Graphene materials are competitive candidates as electrodes of supercapacitors for their high specific surface area, electrical conductivity and stability. Either heteroatoms doping or incorporation with metal/metal oxides have been reported effective in further improving the capacitive performance of graphene-based electrode. Here, an active-screen plasma (ASP) technique was applied on graphene oxide (GO) as a low temperature, environmentally friendly and one-step multi-purpose treatment. Characterization of ASP-treated GO revealed reduction in GO, nitrogen doping mainly in graphitic N configuration, and incorporation of multiple metal element (Fe, Mn, and Cr). Both electrical and electrochemical properties were improved considerably, with sheet resistance decreased to ~ 1.1 × 10⁶ Ω sq⁻¹, only a fifth of that of GO, and a specific capacitance increased to ~ 20 F g⁻¹, four times that of GO. These results suggest advanced ASP technique a simple and facile way for a simultaneous reduction and nitrogen doping of GO, with incorporation of metal/metal oxides nanoparticles towards energy storage applications.