Nitrogen-Doped Microporous Carbons Synthesized From Indolebased Copolymer Spheres For Supercapacitors And Metal-Free Electrocatalysis

Indole-based copolymer spheres serve as a precursor for the facile and easily scalable synthesis of a series of nitrogenrich microporous carbons. The influence of chemical activation and carbonization parameters on the morphology, chemical composition, and electrochemical behavior of the porous carbons has been monitored. The copolymers exhibit an inherent porous framework, which ensures abundant microporosity and BET surface area as high as 1255 m(2) g(-1) in the porous carbon materials. Homogeneously distributed high nitrogen doping in the copolymer was maintained up to 3.8% even at a high carbonization temperature of 900 degrees C. The carbon material ITS-2-700 displays high specific capacitance in aqueous acidic (420 F g(-1)) and alkaline (357 F g(-1)) electrolytes. Moreover, the complete capacitance retention in both electrolytes emphasizes its feasibility as suitable supercapacitor materials. At a higher carbonization temperature of 900 degrees C, the porous carbon material (ITS-2-900) shows excellent ORR catalytic activity with a 0.99 V (vs RHE) onset potential and a high limiting current density (5.1 mA cm(-2)). ITS-2-900 exhibits superior durability and resistance toward methanol oxidation when compared with the commercial Pt/C electrocatalyst.