One-step synthesis of biomass derived O, N-codoped hierarchical porous carbon with high surface area for supercapacitors

Abstract

We report a convenient method to synthesize O, N-codoped hierarchical porous carbon by one-step carbonization of the mixture of KHCO3, urea and alginic acid. Benefiting from KHCO3 and urea synergistic effect, the obtained O, N-codoped hierarchical porous carbon (NPC-700) material has a well-developed interconnected porous framework with ultrahigh specific surface area (2846 m2/g) and massive heteroatoms functional groups. Consequence, such porous carbon displays high specific capacitance (324 F/g at 1 A/g), excellent rate performance (212 F/g at 30 A/g) and good electrochemical stabilization in 6 mol/L KOH solution. More importantly, the assembled NPC-700//NPC-700 symmetrical supercapacitor can achieve a high energy density of 18.8 Wh/kg and good electrochemical stabilization in 1 mol/L Na2SO4 solution. This process opens up a new way to design heteroatoms-doped hierarchical porous carbon derived from biomass materials for supercapacitors.