Formation of three-dimensional honeycomb-like nitrogen-doped graphene for use in energy-storage devices

We have developed a one-step method to produce three-dimensional honeycomb-like nitrogen-doped graphene. Interlaminated hybrid composites of phthalocyanine (Pc) and graphene oxide (GO) swell up when hydrogen is released from the layers during the solid-state pyrolysis process, producing the three-dimensional graphene. The unique micro-structural features of the honeycomb-like nitrogen-doped graphene possesses a high surface area of ∼230 m2 g−1 and a substantial content of nitrogen (∼4.03%). The planar-N configuration is found to significantly enhance the electrochemical property, due to the improved electrical conductivity and enhanced capacitance in KOH aqueous electrolyte in reversible Faradic redox reactions. The supercapacitor based on the honeycomb-like nitrogen-doped graphene presented outstanding specific capacitance (175 F·g−1 at 0.5 A·g−1) and a long cycle life of more than 5000 cycles. This work provides an opportunity for the mass production of 3D nitrogen-doped graphene for industrial application.