Adsorption of NH2NO2 molecule on the surface of pristine and Pt functionalized (6, 0) zigzag GaNNTs: A NMR study

In the recent years, the study of characteristics of nanotubes in gas phase and their use in gas sensors, storage of fuels, and removal of hazardous pollutants from gas streams is important at many industrial processes [1–3]. So far, many different aspects of nanotube/adsorbents have been experimentally explored [4–5]. Moreover, different kinds of nanotubes such as (CNTs), (BNNTs), BeONTs, GaNNTs and SiCNTs have been theoretically investigated for gas molecule adsorption. In this computational study, the representative models of NH2NO2 adsorption on the surface of pristine and Pt functionalized (6, 0) zigzag GaNNTs are allowed to relax in the optimization at the DFT level of B3LYP exchange functional and LAL2DZ standard basis set. From optimized structures the quantum and nuclear magnetic resonance parameters of system are calculated. The chemical shielding tensors in principal axes system (PAS) are converted to measurable NMR parameters, chemical shielding isotropic (CSI) and chemical shielding anisotropic (CSA) by Eqs 1 and 2. (1) (2) The calculated results demonstrate that with functionalizing Pt atoms on the surface of Ga and N atoms of nanotube the structural, electrical and optical parameters of nanotube alter significantly from original state. On the other hand, with functionalizing Pt atoms the CSI values of Ga and N atoms increased significantly from original values, an so the electron charges around nanotube increased due to donor electron effect of Pt atoms. This result confirms that the surface of nanotube is a good position to adsorb the nucleophile compound. The quantum parameters such global hardness and gap energy of system decrease. However, the NMR calculated results demonstrate that the interaction between GaN nanotube and Nitroamide molecule in presence of Pt atom is more favorable than other nanotube.