▎ 摘 要
By doping graphene with iodine and ammonia, I and N co-doped graphene (ING) is prepared and used as metal free catalyst for the oxygen reduction reaction (ORR) both in alkaline and acidic media. The as-prepared catalyst exhibits striking activity in alkaline with an onset potential of 0.945 V (vs. RHE) which is the same with commercial Pt/C catalyst. In acidic media the ING shows a competitive activity. In both alkaline and acidic media the ORR is four-electron process catalyzed by ING. The superior ORR performance of the ING can be attributed to the synergetic doping effect of I and N. Based on its outstanding performance the ING can work as a metal free catalyst for fuel cell with much lower cost than currently used Pt/C catalyst. (C) 2015 Elsevier Ltd. All rights reserved.