On the large capacitance of nitrogen doped graphene derived by a facile route

Abstract

Recent research activities on graphene have identified doping of foreign atoms into the honeycomb lattice as a facile route to tailor its bandgap. Moreover, the presence of foreign atoms can act as defective centres in the basal plane, and these centres can enhance the electrochemical activities of the surface of graphene. Here, we report a facile synthetic approach towards the bulk synthesis of nitrogen doped graphene (N-Graphene) from graphene oxide using a hydrothermal process, with significant control over the extent of N-doping. The electrochemical activeness of N-Graphene (with 4.5 atomic% of nitrogen) is studied by conducting supercapacitor measurements. N-Graphene exhibits a remarkably high specific capacitance of 459 Fg⁻¹ at a current density of 1 mA cm⁻² in an electrolyte of 1 M H₂SO₄ with a high cycle stability compared to that of pristine graphene, which has a specific capacitance of 190 Fg⁻¹. The structural destabilisation of graphene in higher pH/high amount alkaline treatment is demonstrated, and hence optimization of the amount of reagents is necessary in developing a graphene based high performance electronic or electrochemical devices.