Graphenylene oxide: A new two-dimensional material

We investigated the oxidation and sulfurization of the graphenylene monolayer. Although this structure is unstable when it is 100 % covered with oxygen, obtaining a stable form of oxidized graphenylene is possible for 50 % of coverage. In this structure, the oxygen atoms are added on alternating sides of the monolayer, adopting an epoxy-like structure. It is stable up to 1635 K and is a minimum on the potential surface energy. It is an insulator with an indirect band gap of 5.3 eV, a value much larger than the band gap of the pristine graphenylene. Its sulfur counterpart is stable up to 1256 K, presenting a smaller indirect band gap of 3.5 eV.