Insights on the enhanced nitrogen dioxide sensing using doped boron nitride nanosheets through the quantum chemical studies

[Display omitted] •Adsorption behaviour of BNNs doped with Cr, Ni, Al, C, Si, O and S was examined towards NO2.•The dopant atoms bintroduced local deformation in the planar geometry of the pristine BNNs.•The interactions between the NO2 molecuele and the doped BNNs were accompanied by the charge transfer.•From the HOMO-LUMO distributions and DOS plots, newly formed energy levels due to the dopant atoms were confirmed.•The thermodynamic adsorption energy values indicated the chemical nature of interactions.•Based on the overall quantum chemical analysis, the C/BNNs was most suitable for the sensing of NO2. A comprehensive analysis of the effect of different dopant atoms (Cr, Ni, Al, C, Si, O and S) on the sensing capacity of boron nitride nanosheets (BNNs) towards NO2 gas is reported in this study. The calculations were based on the Kohn-Sham density functional theory calculations. The quantum chemical analysis was based on the molecular electrostatic potential maps, HOMO-LUMO distributions, DOS plots, Mullikan charges and quantum descriptors were studied. The NO2 positioning over the nanosheets was optimized at CAM_B3LYP/6-31G level of theory. The infrared spectra obtained from the first principle computations indicated a frequency shift for the NO symmetric stretching vibrations. The computed Mullikan charges showed a charge transfer from nanosheets to NO2. HOMO-LUMO energies and their distributions confirmed the charge transfer. The reactivity descriptors for Cr and Si-doped BNNs suggested their better ability to adsorb NO2 than other nanosheets. The thermodynamics of the sensing was studied using the adsorption energies that ranged between −0.3 to −2.6 eV, confirming the chemical nature of sensing. Overall, the analysis showed that Cr/BNNs and Ni/BNNs exhibited greater sensing activity towards NO2 than the other doped BNNs.