▎ 摘　　要

Graphene is an excellent material, which can be used in aerospace field. However, it was reported that when graphene works in an oxygen-rich environment, its surface inevitably absorbs oxygen atoms. And oxygen atoms are doped when graphene has defects. In this study, we investigate the effect of adsorption and doping of oxygen atoms on the properties of graphene using first-principles calculations. We found that the adsorption of single oxygen atom can only change the position of Dirac point. However, the adsorption of multiple oxygen atoms may lead to band gaps. Meanwhile, when graphene has defects, oxygen atoms can repair its lattice. But oxygen atoms also localize some electrons, giving graphene a larger band gap than pure defective graphene. This study is helpful to evaluate the properties of graphene in an oxygen-rich environment. At the same time, it has certain significance for the application of graphene in band gap engineering.