Adsorption-doping for preparing N-doped porous carbon for promising electrochemical capacitors-using peptone and polymer porous resin as precursors

•The adsorption-doping was implemented to prepare N-doped porous carbon.•Polymer resin and peptone are used as carbon and nitrogen sources, respectively.•Specific capacitance of 344 F g−1 is obtained from the carbon-based electrode.•The carbon-based device shows a maximum energy density of 9.1 W h kg−1. The adsorption-doping has been shown an effective strategy for preparing nitrogen doped porous carbons. In the present study, commercial porous polymer spherical resin was used as adsorbent, and nitrogenous organic-peptone was employed to be the nitrogen source. Adsorption, carbonization and chemical etching were sequentially proceeded. Elements contents of nitrogen and oxygen in the obtained amorphous porous carbon were 2.93 at.% and 4.85 at.%, respectively. The specific surface area was 1,425 m2 g−1, of which the contribution mainly came from micropores with size of 4–7 Å. As an electroactive material, electrodes enclosed the porous carbon harvested specific capacitances of 343.9 and 253.5 F g−1 at a current density of 1 A g−1 in the three-electrode and symmetric-two-electrode systems, respectively. In basic aqueous electrolyte, the supercapacitor device achieved a maximum specific energy of 9.1 W h kg−1 at a specific power of 123.2 W kg−1. Findings of the study further illustrate the feasibility of the adsorption doping strategy. Results also acknowledged that the strategy could be used as a universal process to develop promising porous carbon materials for high performances supercapacitors. [Display omitted]