Pyrrolic-structure enriched nitrogen doped graphene for highly efficient next generation supercapacitors

This study reports the preparation of pyrrolic-structure enriched nitrogen doped graphene by hydrothermal synthesis at varied temperature. The morphology, structure and composition of the prepared nitrogen doped graphene were confirmed with SEM, XRD, XPS and Raman spectroscopy. The material was tested for supercapacitive behavior. It was found that doping graphene with nitrogen increased the electrical double layer supercapacitance to as high as 194 F g^-1. Furthermore, density functional theory (DFT) calculations showed the proper level of binding energy found between the pyrrolic-nitrogen structure and the electrolyte ions, which may be used to explain the highest contribution of the pyrrolic-structure to the capacitance.