First-principles study of the oxygen adsorption and dissociation on graphene and nitrogen doped graphene for Li-air batteries

Recently, Yoo and Zhou [ACS Nano 5, 3020-3026 (2011)] reported that graphene can be directly used as electrode for Li-air batteries, suggesting that graphene itself can be served as catalyst for O-2 dissociation reaction. In this work, we show from density functional theory calculations that the O-2 dissociation reaction energy barrier is substantially decreased on the graphene surface comparing to that of in vacuum. Furthermore, N-doping can further decrease the energy barrier from 2.39 eV (undoped case) to 1.20 eV. The O-2 molecule physical adsorption, O atom chemical adsorption at the graphene, and N-doped graphene surfaces are also simulated. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4766919]