Significance of N-moieties in regulating the electrochemical properties of nano-porous graphene: Toward highly capacitive energy storage devices

The effects of N doping concentration and dopant moieties on the electrochemical properties of nanoporous graphene and their dependence on annealing temperature are investigated. Four types of N moieties – amide, amine, graphitic-N, and oxidized-N – are obtained, which transformed into pyridinic-N and pyrrolic-N upon annealing. The diffusion coefficient (D′) of the ions in the electrode is the maximum at 400 °C because of a high level of N doping, whereas the second highest D′ value is obtained at 700 °C owing to a high level of reduction and N doping. The highest specific capacitance is obtained for the sample annealed at 400 °C.