Effects of graphitic- and pyridinic-N co-doping on structure regulation and ORR activity of N-doped graphene

Nitrogen-doped graphene (NDG) has been widely used in electronic devices, optoelectronic devices, catalysts and other fields, due to its high stability, easy synthesis process and other excellent properties. Currently, the synthesized NDG often has extremely complex structures, such as various nitrogen types and different pore structures. Synthesizing NDG with specific structures to realize their applications in specific fields remains challenging. In this paper, the co-doping effect of graphitic-N and pyridinic-N on the structural stability of NDG is investigated from the perspective of theoretical calculations. By studying the co-doping of graphitic-N and pyridinic-N in different porous structures, it is found that co-doping is beneficial to improve the stability of the material. The co-doping of graphitic-N and pyridinic-N in triangular pore is the most stable structure among all co-doped structures. Further, we investigated the oxygen reduction reaction (ORR) activities of graphitic-N, pyridinic-N, and co-doped structures, respectively. The co-doped structure is found to have higher ORR activity than the graphitic-N or pyridinic-N doped structure. Our study provides important theoretical guidance for the synthesis of NDG structures with high ORR activity.