Sol-gel process-derived rich nitrogen-doped porous carbon through KOH activation for supercapacitors

•Nitrogen-doped porous carbons are prepared from poly(acrylic acid)/melamine resin through sol-gel process and KOH activation.•The porous carbon (C-700-1.5) with high specific surface area and nitrogen content exhibits intriguing electrochemical performance.•C-700-1.5 demonstrates superior specific capacitance, excellent rate capability and outstanding cycling durability.•High specific surface area, synergy of the micropore and mesopores, nitrogen functionalities contribute to the superior performance of C-700-1.5.

A rich nitrogen-doped porous carbon with high specific surface area and superior specific capacitance for supercapacitors is synthesized from poly(acrylic acid)/methylated melamine-formaldehyde resin through sol-gel process at ambient temperature for 24 hrs, followed by calcination and carbonization at 350 °C and 500 °C for 1 hour respectively and KOH activation at 700 °C for 2 hours under N2 atmosphere. The porosity and surface chemistry of the rich nitrogen-doped porous carbon are swiftly manipulated by KOH activation, with the specific surface area increasing from 14.2 to 2674 m2 g−1 and nitrogen content varying from 20.3 to 8.8 by wt.%, respectively. The porous morphology and nitrogen functionalities enable the nitrogen-doped porous carbon to perform an intriguing electrochemical performance in 1 M H2SO4 aqueous electrolyte, such as a superior specific capacitance at the current density of 0.2 A g−1 (280 F g−1), excellent rate capability (171 F g−1 remained at 10 A g−1) and outstanding cycling durability (no capacity decay after 9000 cycles), which make it a promising electrode material for high performance supercapacitors.

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