A Facile Method for N-Doped Graphitized Activated Carbon and the Application in Supercapacitors

N-doped graphitized activated carbon based on DDGS is an extremely attractive material for energy storage due to the high specific capacitance and low cost. The as-prepared carbon samples are derived from DDGS, which is the byproduct from a fermentation process optimized for bio-fuel production. The reagent potassium hydroxide and the catalyst nickel nitrate hexahydrate were used to obtain the N-doped graphitized activated carbon samples. The high specific surface area (1315 m² g^-1) of N-doped graphitized activated carbon was achieved. The scanning electron microscopy, transmission electron microscopy and Raman spectroscopy instruments were used to test the microstructure and crystallographic orientation of the carbon samples. EDS and XPS were used to analysis the elemental content covalent electron states. The cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy were measured after the N-doped graphitized activated carbon being assembled to supercapacitors. The N-doped graphitized activated carbon sample presents a high specific capacitance of 320 F g^-1, and a relatively low inner resistance of 0.1 ohm.