Simple solution-based synthesis of pyridinic-rich nitrogen-doped graphene nanoplatelets for supercapacitors

Abstract

Pyridinic-rich nitrogen-doped graphene nanoplatelets (PRGOs) were synthesized using an acid-catalyzed dehydration reaction between GO and 3,4-diaminopyridine. Specific pyridinic nitrogen configurations can be efficiently introduced to graphitic network through newly formed imine and pyrizaine linkages. The structure of PRGOs was confirmed by various microscopic and spectroscopic analyses. In addition, the nitrogen content in PRGOs can be readily controlled over a wide range (1.9-9.1wt.%) by simple change in the feed ratios of reactants. Owing to the simultaneous structural restoration and nitrogen doping onto graphitic structure, PRGOs show high performance of supercapacitors, including enhanced specific capacitance and long-term stability. Furthermore, the effect of nitrogen contents on specific capacitance has also been investigated to optimize doping levels of nitrogen atoms in PRGOs. The highest specific capacitance of 214Fg-1 at current density of 0.1Ag-1 has been achieved from PRGO-5 with a moderate nitrogen content of 5.3wt.%, due to its balanced electric double layer capacitance and pseudocapacitance.