Adsorption of the Rare Gases (He, Ne, Ar, and Kr) onto the Pristine and Gallium-Doped Aluminum Nitride Nanotubes: A DFT, NBO, and QTAIM Study

The adsorption of He, Ne, Ar, and Kr onto the exterior surface of the pristine and the Gallium (Ge)-doped aluminum nitride nanotubes (AlNNTs) in the form of single-walled armchair (5,5) were comparatively investigated by using the density functional theory (DFT) method. All of the nanostructures were geometrically optimized using Perdew–Burke– Ernzerhof exchange-correlation correction functional (i.e. PBEPBE) in the generalized gradient approximation (GGA) framework along with 6-31G (d) basis set. The natural bond orbital (NBO) as well as quantum theory of atoms in molecules (QTAIM) analysis were also implemented so as to much better discerning of the intermolecular interaction between aforementioned rare gases (RGs) and the pristine/Ga-doped nanotubes. As a case in point, the closed-shell(non-covalent) interactions between nanotubes and RGs have been remarkably confirmed in the QTAIM analysis. Themagnitude of calculated adsorption energies (Eads) in this investigation shows this trend: Ne > Kr > Ar > He. The values of the Wiberg bond index, partial natural charges, and donor-acceptor interactions of all structures were also extracted from NBO analysis. By considering the calculated data, all results consistently approve that the Ga-doped nanotubes are more sensitive than the pristine nanotubes.

Keywords:

Aluminum nitride , DFT , Ga-doped , NBO , QTAIM