Nitrogen‐Doped Porous Carbon Derived From Benzotriazole Activated by Potassium Ferrate for High‐Performance Supercapacitors

Nitrogen‐doped porous carbons were synthesized using benzotriazole (BTA) as a single‐source precursor for both carbon and nitrogen, activated by potassium ferrate (K 2 FeO 4 ) at varying mass ratios. The optimized material, BPC‐1, obtained at a BTA/K 2 FeO 4 ratio of 1:1, features a hierarchical micro/mesoporous architecture with a high specific surface area of 2691.8 m 2 /g and uniform N (5.98 at%) and O (16.04 at%) doping. In a three‐electrode system with 6 M KOH, BPC‐1 delivers a specific capacitance of 400 F/g (0.5 A/g) and retains 93.14% of its initial capacitance after 10,000 cycles (10 A/g). A symmetric supercapacitor assembled with BPC‐1 achieves an energy density of 22.8 Wh/kg at a power density of 505.3 W/kg in 1 M Na 2 SO 4 , significantly outperforming its alkaline electrolyte counterpart. The combination of in situ heteroatom self‐doping and oxidative pore engineering establishes a robust platform for advanced carbon‐based supercapacitors.