Nitrogen Doped Graphene with High Performance for Oxygen Reduction Reactions

Abstract

Heteroatom doped carbons represent as metal-free electrocatalysts for oxygen reduction reaction (ORR). The heteroatom makes these catalysts non-electron-neutral and subsequently favors the molecular adsorption of oxygen and its reduction. Meanwhile, synergetic effect between different heteroatoms on carbon facilitates ORR activity. Thus, it is necessary to find out the best structure for heteroatom doped metal-free catalysts for ORR. Herein, graphene was synthesized and subsequently doped by sulfur (S) and nitrogen (N). Graphene, N-doped graphene, S-doped graphene, and N, S-codoped graphene were comparatively studied on their ORR performances. As a result, doped graphene demonstrates better catalytic activity than graphene. Besides, N-doped graphene shows higher activity than S-doped graphene and N, S-codoped graphene. Therefore, N-doped graphene can be utilized as highly efficient metal-free electrocatalyst for ORR.