Physico-chemical nanomaterials science
First-principles study of two-dimensional haeckelite BeO monolayer
Piatnytskyi D.M.1, Afanasieva T.V.1,2
1 Taras Shevchenko University of Kyiv, Glushkova Avenue 4G, Kyiv-03187,
Ukraine.
E-mail: taifumerang03@gmail.com
2 Physical Electronics Department, Institute of Physics of the NAS of Ukraine. Prospect Nauki, 46, Kyiv-03039, Ukraine. 
E-mail: tetiana.v.afanasieva@gmail.com

The two-dimensional (2D) materials have drawn great attention in material science due to their exotic electronic properties. II-VI semiconductors are interesting candidate materials for the tailoring of two-dimensional hexagonal structures. Recently, a two-dimensional BeO hexagonal monolayer on Mo(112) support was obtained [1]. The alternative two-dimensional materials like several graphene allotropes, GaN, and NbS2 haeckelites have been predicted to be stable using theoretical investigation. Haeckelite-like structures and line defects also have been observed in different freestanding materials and on support. These new 2D materials have attracted interest in opening the possibility to find semiconductor materials with unexplored properties. 
First-principles density functional theory calculations were performed to investigate the stability, electronic properties, and catalytic activity of two-dimensional haeckelite BeO monolayer (containing 8-4 membered rings). The calculations were carried out using the ABINIT package. The optimized geometry, band structure, local density of states (LDOS), binding energies, and charge density were calculated. The interatomic distances between Be and O atoms are 1.48 and 1.56 Å. The lattice parameter is found to be 5.20 Å. The conduction band minimum is at Gamma point. The indirect band gap for the freestanding haeckelite BeO monolayer is found to be 5.48 eV by GGA-PBE calculation. The direct band gap at G point was estimated to be 5.71 eV. The catalytic activity of the BeO monolayers was investigated. So, the interaction of the haeckelite BeO structures with hydrogen and carbon monoxide molecules were simulated. The binding energies for H2 and CO molecules on the haeckelite BeO monolayer were obtained.

1.	T.V. Afanasieva, A.G. Fedorus, D.V. Rumiantsev, I.N. Yakovkin, Honeycomb BeO monolayer on the Mo(112) surface: LEED and DFT study // Appl. Surf. Sci. – 2018. – 428, p.815–818.