Facile and controllable synthesis N-doping porous graphene for high-performance supercapacitor

Engineering graphene with efficient ion and electron transport properties is vital for development of high performance, next generation energy storage devices. The protocols generally involve pore generation and doping of graphene with the heteroatoms. Herein we report the realization of pore generation, control, and N-doping of graphene in one single process using reduced metal salt as etching agent and environment friendly N₂ gas as doping agent. Furthermore, we found the porous structure (pore size and density), the dopant bonding configuration and doping amount can be controlled by change the metal salt and nitrogen source, which allows us to investigate the influence of pore and N-doping structure of porous graphene (PG) in their supercapacitor performance. Specifically, the N-doping, PG prepared by Ni salt (PG-Ni) shows the smaller pore size (average pore size of ~20–30 nm) and larger pore density. PG-Ni exhibits high specific capacitance of 575 F/g along with the energy density of 51.2 Wh/kg at 0.5 A/g current density and also shows good rate, cycling performances. Considering the excellent performance, ease of the process, and pore structure controllability, we believe the method provides a new route for developing graphene based high performance supercapacitors.