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

Abstract

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.