DFT studies on the interactions of pristine, Al and Ga-doped boron nitride nanosheets with CH3X (X=F, Cl and Br)

The adsorption of CH3F, CH3Cl and CH3Br halomethanes on pristine boron nitride (BNNS), aluminum-doped boron nitride (BN(Al)NS) and Gallium-doped boron nitride (BN(Ga)NS) nanosheets were investigated by two-dimensional periodic boundary condition density functional theory methods. All nanosheets were geometrically optimized at B3LYP/6-311 + G (d) level, and single point energy calculation at M06-2X, omega B97X-D3 and CAM-B3LYP/6-311 + G(d) levels of theory were also performed. NBO and QTAIM analyses were also performed, and values of the Wiberg bond index (WBI), partial natural charges and donor-acceptor interactions were further analyzed. The obtained adsorption energy values (E-ads) indicate that the tendency of nanosheets to adsorb CH3F and CH3Br to their surfaces are in the order of BN(Ga) NS > BN(Al)NS> BNNS. However, for CH3Cl, which adsorb with a significant lower E-ads compared to the other halomethanes, this trend is as follows: BN(Al)NS> BN(Ga)NS > BNNS. Moreover, it was found that, the affinity of halomethanes to adsorb onto the surface of nanosheets is in the order of CH3Br > CH3F >> CH3Cl. Generally, it seems that BN(Al)NS and BN(Ga)NS are promising candidates in designing a new type of solid state halomethane gas sensors. (C) 2019 Elsevier B.V. All rights reserved.