Modeling the structure and electronic properties of new polymorphic L4-8 hydroxygraphene varieties

Modeling of the structure and electronic properties was carried out from the first principles for the polymorphic varieties of graphene functionalized by hydroxyl groups (hydroxygraphene), where basic graphene layer structure consisted exclusively of 4 to 8 paired topological defects. Calculations of L4-8 hydroxygraphene layers were performed by the density functional theory method utilizing generalized gradient approximation. As a result of modeling, the possibility of the stable existence of five varieties of hydroxygraphene L4-8 layers was established. However, one structural variety of hydroxygraphene L4-8‑T3, which has c2 / m11 symmetry, is unstable. Lengths of the elementary translation vectors for L4-8 hydroxygraphene layers are greater than the corresponding values for similar fluorine-functionalized layers by 0.02 – 0.15 Å. The layer density in L4-8 hydroxygraphene layers is less than the one for similar fluorographene layers by 0.05 – 0.14 mg / m2. The sublimation energies of the layers range from 17.44 to 18.52 eV / (COH). The layer T4 is expected to be the most stable with the maximum sublimation energy. The width of the band gap is minimal for the layer T1 (3.24 eV), while T6 has maximum width of the band gap (4.48 eV). The band gap range of variation for the hydroxygraphene layers turned out to be narrower compared to fluorographene layers.

1. Russian Foundation for Basic Research - 20-32-90002
2. Foundation for Advanced Scientific Research of Chelyabinsk State University -