Electronic structures and bonding of graphdiyne and its BN analogs: Transition from quasi-planar to planar sheets

Abstract

We demonstrate a possible structural transition from graphdiyne (GDY) to boron nitride (BN)-diyne (C90-18n(BN)9nH18; n = 0-5) sheets using the density functional theory (DFT). The aim of this study is to investigate the effects of substitution of carbon atoms by B and N atoms on structural, electronic and reactivity properties. We found that a structural transition from quasi-planar to planar occurs at n = 2. The stability decreases with increasing the number of B/N. Moreover, the pristine BNdiyne is only less stable than pristine GDY by about 0.92 eV/atom. Our calculations also show that the energy gap of the GDY and its BN structural analog models changes in the wide range of 0.45–5.52 eV as the number of B and N atoms increases in the system. The of the BNdiyne (n = 5) is found to be 5.52 eV, indicating electrically an insulating behavior, however, it is 0.45 eV for the BNdiyne (n = 4) which is higher conductivity than that of pristine GDY. Molecular dynamics simulations show that temperature induces a decrease in the due to variations of the bond energy and deformation in the structures under heat treatment. The ELF analysis also confirms that the B–N bonds in new GDY-like BN sheets potentially exhibit covalent characteristics. Our results herein show that new BNdiyne sheets can be used in promising applications from chemical nanosensors to solar cell applications.