N, P-dual doped carbon with trace Co and rich edge sites as highly efficient electrocatalyst for oxygen reduction reaction

Abstract

Oxygen reduction reaction (ORR) is key to fuel cells and metal-air batteries which are considered as the alternative clean energy. Various carbon materials have been widely researched as ORR electrocatalysts. It has been accepted that heteroatom doping and exposure of the edge sites can effectively improve the activity of carbon materials. In this work, we used a simple method to prepare a novel N, P-dual doped carbon-based catalyst with many holes on the surface. In addition, trace level Co doping in the carbon material forming Co–N–C active species can further enhance the ORR performance. On one hand, the doping can adjust the electronic structure of carbon atoms, which would induce more active sites for ORR. And on the other hand, the holes formed on the surface of carbon nanosheets would expose more edge sites and can improve the intrinsic activity of carbon. Due to the heteroatom doping and the exposed edge sites, the prepared carbon materials showed highly excellent ORR performance, close to that of commercial Pt/C.