Preparation of nitrogen-doped porous carbon via adsorption-doping for highly efficient energy storage

Namely “Adsorption-doping Strategy”, a general doping route by absorbing nitrogen-containing organic substances onto organic porous adsorbent materials is proposed for the synthesis of nitrogen-doped porous carbon. The three steps of this strategy can be described as adsorption, pre-carbonization and activation. Herein, nitrogen-doped porous carbon derived from commercial macroporous adsorption resin and gelatin as adsorbent and adsorbate, respectively, exhibits excellent electrochemical capacitive performance. The nitrogen-contained porous carbon delivers a significantly improved specific capacitance as high as 362 F g−1 at a current density of 1.0 A g−1, considerably larger than the capacitance of carbon electrodes that from the direct mixture of dried gelatin (271 F g−1) and macroporous adsorption resin (251 F g−1) at the same current loading. The synergistic effect of high specific surface area, well-balanced pore size distribution, low resistance and appropriate content of nitrogen and oxygen functionalities with a reasonable distribution in the carbon walls attribute to the high capacitance.