Structure and stability of graphene-like layers built from heterocyclic units

Encouraged by the developments in the synthesis of novel two-dimensional (2D) materials through bottom-up approaches, we investigate the structural properties and stability of a variety of 2D monolayers constructed from aromatic six-membered rings using density functional theory methods. We study benzene, single heteroatom heterocycles, as well as borazine, 1,3-diazine, and 1,3,5-triazine as building blocks of graphene-like monolayers. Through an analysis of the relative stability of the 2D layers with respect to their molecular constituents, we find that diazine and borazine monolayers present the greatest stability of all studied compounds. These large bandgap holey materials open the possibility of a whole family of 2D sheets based on seamlessly connected six-membered rings that can show promise in applications such as catalysis and gas separation.