N-doped 3D porous carbon catalyst derived from biowaste Triarrhena sacchariflora panicle for oxygen reduction reaction

Abstract

Developing metal-free catalysts possessing high oxygen reduction reaction (ORR) catalytic activity and splendid stability has become one of the most attractive topics in contemporary society. In this study, Triarrhena sacchariflora panicles were hydrothermally treated in KOH aqueous solution. The KOH activation was simplified. After carbonization and nitrogen doping process, the N-doped carbon material was obtained. The material presents a 3D interconnected hierarchical porous structure and an excellent ORR catalytic activity (E1/2 = 0.83 V), along with a high stability (6% loss of current density after 10,000 s) in alkaline media. Compared to the commercial Pt/C catalyst (20 wt%), the catalyst exhibits a similar ORR catalytic activity and much higher stability in alkaline media. Taking this method can not only dispose of the biowaste well but also reduce the amount of KOH compared with the traditional KOH activation method, resulting in low cost and little environmental pollution.