Adsorption of atmospheric oxidants at divacancy sites of graphene: A DFT study

Periodic DFT calculations are performed to compare the reactivity with respect to atmospheric oxidants like O2, H2O, O3 and atomic oxygen of different divacancy structures created in graphene sheet by removing two adjacent carbon atoms. The present approach shows that O and O3 can easily be chemisorbed at the divacancy sites, the reaction product being however strongly dependent on the divacancy structure. The situation appears more intricate when considering the interaction of O2 and H2O with the defective graphene sheet. In this case, dissociative chemisorption on the surface is evidenced only when dangling bonds are present at the divacancy site.