N-doped carbon derived from regeneration nylon 6 used as an electroactive material for electrochemical capacitor

A regenerated nylon 6 that derived from waste nitrogenous polymers is firstly used as a precursor to prepare N-doped porous carbon for electrochemical capacitors. The nitrogen that mainly consisted of pyrrole nitrogen in the obtained amorphous carbon is identified to be 3.67 at.%. The Brunauer-Emmett-Teller specific surface area of the porous carbon is determined to be 1536 m2 g−1 with a total volume of 0.89 cm3 g−1. In a three-electrode system that using 6.0 M KOH solution as an electrolyte, electrode enclosed the N-doped carbon as electroactive material delivers specific capacitance of 304 and 267 F g−1 are at current densities of 0.5 and 10 A g−1, respectively. With the same electrolyte and current density, the specific capacitance of the electrode in a two-electrode system was evaluated to be 245 and 216 F g−1, respectively. A maximum energy density was calculated to be 8.4 W h kg−1 with a power density of 122 W kg−1 suggesting an excellent capacitive energy storage capacity. Considering the reusability of waste resources, the regenerated nylon can be regarded as one of the competitive candidates for the preparation of porous carbon for high-performance electrochemical capacitors. [Display omitted] •Regenerated nylon is employed as a precursor to prepare N-doped electroactive carbon.•The doped nitrogen element is mainly composed of pyrrole nitrogen.•The resulting carbon electrode harvests a specific capacitance of 304 F g−1 at 0.5 A g −1.•The supercapacitor device yields 8.4 W h kg−1 energy density in an aqueous electrolyte.