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

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 syne rgistic 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.