N-Containing Carbon/Graphene Nanocomposites for Electrochemical Supercapacitor Applications

Abstract

Hetero atoms containing conductive nanocarbon materials are being studied extensively for their electrochemical energy storage and conversion applications. Herein, we report a facile process for the preparation of N-containing carbon/graphene nanocomposites by simultaneous thermal decomposition of polypyrrole into N-containing carbon and reduction of graphene oxide into graphene in H2/Ar atmosphere. The XRD pattern of N-containing carbon/graphene nanocomposites prepared at different temperatures indicated the formation of reduced graphene oxide from the reduction of GO. The FT-IR and Raman spectroscopic analysis revealed the presence of N atoms in the nanocomposites and the elemental analysis was used to estimate the amount of N in the nanocomposite. The XPS analysis distinguished the pyridine, pyrrolic and quaternary forms of N present in the nanocomposite. The slow decomposition of polypyrrole resulted in the mesoporous structure to the resulting nanocomposite, which was confirmed by the BET adsorption–desorption isotherm. The electron microscopic analysis confirmed the presence of highly transparent carbon nanosheets. The amount of N in the nanocomposite that depends on the decomposition temperature was found to influence the electrochemical performance. The nanocomposite prepared at 700 °C showed a large specific capacitance of 296 F/g with an excellent cycling stability of 93% after 1000 cycles.