Oxygen adsorption on honeycomb ^BC2N monolayers

We present the electronic structure and energetics of atomic oxygen adsorption on graphene-like ^BC2N honeycomb monolayers in view of density functional calculations using GGA scheme. After the geometry optimization of bare ^BC2N monolayer, we consider eight initial configuration for binding of atomic oxygen. As initial configurations, atomic oxygen is located ≈1Å above the following sites; mid of the B-N, B-C, C-C, N-C bonds, B, N, C atoms, and hollow of the hexagonal cell. Among the bare structures, type-II is determined as the most stable structure energetically. This can be conceived by visualization of electronic environments of each atom, since type-II geometry optimizes the number of C-C and B-N bonds. When the oxygenated structure is concerned, atomic oxygen is located at the bridge site of B-C bond of type-II geometry yielding most favorable structure energetically. The adsorption energies and reaction paths of oxygen are also investigated. The results show that the oxygenation of type-I structure induces a semiconducting band gap, while semiconducting nature of type-II and type-III is preserved under oxygen adsorption.