Selectivity and Sensitivity Evaluation of Embedded BN-Nanostructure as a Gas Detector for Air Pollution Scavenging: a Theoretical Study

Abstract

This article aims to investigate the structural, electromagnetic, and thermodynamic properties of toxic gases molecules including nitric oxide (NO), nitrogen oxide (NO₂), and nitrous oxide (N₂O) during adsorption on the surface of boron nitride (B₅N₁₀) nanocage which has been decorated with aluminum (Al), carbon (C) and silicon(Si) atoms. The results denote that (NO,NO₂,N₂O) ↔ (Al, C, Si)–B₄N₁₀ are stable complexes with the most stable adsorption site being the center of the cage ring. The partial density of states can estimate a certain charge assembly between gas molecules and (Al, C, Si)–B₄N₁₀ which indicates the competition among dominant complexes of metallic (Al), nonmetallic (C), metalloid/semiconductor (Si). Based on nuclear quadrupole resonance analysis, carbon-doped on B₄N₁₀ has shown the lowest fluctuation in electric potential and the highest negative atomic charge including 0.1190, 0.1844, and 0.1312 coulomb in NO ↔ C–B₄N₁₀, NO₂ in NO ↔ C–B₄N₁₀, and N₂O in NO ↔ C–B₄N₁₀, respectively, can be an appropriate option with the highest tendency for electron accepting in the adsorption process. Furthermore, the reported results of nuclear magnetic resonance spectroscopy have exhibited that the efficiency of electron accepting for doping atoms on the (Al, C, Si)–B₄N₁₀ through gas molecules adsorption can be ordered as: Si > Al \( \gg \) C that indicates the power of covalent bond between aluminum, carbon, silicon and these NO, NO₂, N₂O towards toxic gas removal from air. In fact, the adsorption of gas molecules can introduce spin polarization on the (Al, C, Si)–B₄N₁₀ which indicates that these surfaces might be applied as magnetic scavenging surface as a gas detector. Regarding infrared spectroscopy, doped nanocages of C–B₄N₁₀ and Si–B₄N₁₀ for NO, Al–B₄N₁₀ and Si–B₄N₁₀ for NO₂, Al–B₄N₁₀ and C–B₄N₁₀ for N₂O, respectively, have the most fluctuations and the highest adsorption tendency for gas molecules which can address specific questions on the individual effect of charge carriers (gas molecule-nanocage), as well as doping atoms on the overall structure. Based on the results of \(\Delta G_{{{\text{ads}}}}^{{\text{o}}}\) amounts in this research, the maximum efficiency of Al, C, Si atoms doping of B₅N₁₀ for gas molecules adsorption depends on the covalent bond between NO, NO₂, N₂O molecules and (Al, C, Si)–B₄N₁₀ as a potent sensor for air pollution removal.