Catalytic graphitization assisted synthesis of Fe3C/Fe/graphitic carbon with advanced pseudocapacitance

We report an environmentally friendly strategy for the synthesis of Fe3C/Fe/graphitic carbon based on hydrothermal carbonization and graphitization of carbon spheres with potassium ferrate (K2FeO4) at 800 degrees C. The obtained sample consisting of Fe3C/Fe nanoparticles and graphitic carbon (FC-1-8) delivered an enhanced pseudocapacitance of 428.0 F g(-1) at a current density of 1 A g(-1). After removal of the Fe3C/Fe electroactive materials, the graphitic carbon (FC-1-8-HCl) possessed a large specific surface area (SSA) up to 2813.6 m(2) g(-1) with a capacity of 243.3 F g(-1) at 1 A g(-1), far outweighing the other amorphous carbon electrodes of FC-0-8 (carbon spheres annealed at 800 degrees C without the treatment of K2FeO4). The graphitic material with a porous structure could offer more electroactive sites and improved conductivity of the sample. This method provided guidelines for the synthesis of superior performance supercapacitors with synchronous graphitic carbon and electroactive species.