Adsorption and Diffusion of Oxygen on Single-Layer Graphene with Topological Defects

In this work, effects of oxygen adsorption and diffusion on the stability, morphology, and charge transfer in single-layer graphene with structural point defects were investigated by density functional theory, specifically for the experimentally characterized monovacancy, double-vacancy, 555–777, 5555–6–7777, and Stone-Wales defects. The theoretical analysis demonstrated strengthened oxygen adsorption on defective graphene as compared to pristine graphene, resulting in trapping of the oxygen onto defects. This was accompanied by significant charge transfer of up to 3e, unlike for pristine graphene. At the same time, atomic oxygen diffuses at different rates dependent on the local environment, however with relatively low barriers (mostly