The first-principle study of N2O gas interaction on the surface of pristine and Si-, Ga-, SiGa-doped of armchair boron phosphide nanotube using DFT method

In present research, the electrical, structural, quantum and Nuclear Magnetic Resonance (NMR) parameters of interaction of N2O gas on the B and P sites of pristine, Ga-, Si- and SiGa-doped (4,4) armchair models of boron phosphide nanotubes (BPNTs) are investigated by using density functional theory (DFT). For this purpose, seven models for adsorption of N2O gas on the exterior surfaces of BPNTs have been considered and then all structures are optimized by B3LYP level of theory and 6–31G (d) base set. The optimized structures are used to calculate the electrical, structural, quantum and NMR parameters. The computational results revealed that the adsorption energy of all studied models of BPNTs is negative; all processes are exothermic and favorable in thermodynamic approach. When N2O gas is adsorbed from its O atom head on the B site of nanotube, N2O gas is dissociated to O atom and N2 molecule. The adsorption energy of this process is more than those of other models and more stable than other models. In A, B and C models, the global hardness decreases significantly from original values and so the activity of nanotube increases from original state. On the other hand, the electrophilicity index (ω), electronic chemical potential (μ), electronegativity (χ) and global softness (S) of the A, B and C models increase significantly from original value and CSI values of the C model are larger than those of other models. The results demonstrate that the Ga-, Si- and SiGa- doped BPNTs are good candidates to adsorb N2O and make N2O gas sensor