Medulla tetrapanacis-derived O/N co-doped porous carbon materials for efficient oxygen reduction electrocatalysts and high-rate supercapacitors

Abstract

O/N co-doped porous carbon materials derived from biomass have become the most promising candidates for electrochemical energy conversion and storage due to their renewability and sustainability. We herein present a simple approach to fabricate O/N co-doped porous carbon materials by direct pyrolysis of medulla tetrapanacis (the stem pith of tetrapanax papyriferus). The porous carbon sample (MT-900) synthesized under optimum conditions shows outstanding electrocatalytic activity toward oxygen reduction reaction (ORR) (onset potential (Eo) = 3 mV; half-wave potential (E1/2) = −128 mV vs. Ag/AgCl), together with excellent long-term stability, and high resistance to methanol crossover and CO poisoning. Furthermore, the MT-900-based supercapacitor electrode also exhibits high-rate performance (83.6% capacitance retention from 1 to 100 A g−1) as well as excellent stability (95.2% capacitance retention after 10000 cycles) in 6 M KOH electrolyte.