Tailoring platelet carbon nanofibers for high-purity Pyridinic-N doping: A novel method for synthesizing oxygen reduction reaction catalysts

The controllable synthesis of single nitrogen (N) type doped carbon nanomaterials (CNMs) is of significant importance to evaluate the effects of different N types on electro-catalytic activity for oxygen reduction reaction (ORR) in experiment. Herein, the chaotic edge planes of the as-synthesized platelet carbon nanofibers (plCNFs) are tailored by acid etching of HF to obtain abundant exposed active edge sites while maintaining the interior graphene patterns intact. The N bonding configuration belonging to pyridinic type is nearly 100% and the concentration of the pyridinic-N in the tailored plCNFs reaches up to 12.61 at.%. Electrochemical tests show that N-plCNFs (HF) exhibits improved ORR activities compared with N-plCNFs and the carbon atoms adjacent to pyridinic-N could be the catalytic active sites for ORR. In addition, the generation mechanism of pyridinic-N in tailored plCNFs is briefly elaborated. (C) 2017 Elsevier Ltd. All rights reserved.