Theoretical studies of hydrazine detection by pure and Al defected MgO nanotubes

Abstract

Density Functional Theory (DFT) and time dependent density functional theory (TD-DFT) calculations using PBE and TPSS functionals have been performed to investigate the effects of the adsorption of hydrazine (N2H4) on the structural and optoelectronic features of the pure and Al defected MgO nanotubes. The calculated results for hydrazine/MgO systems reveal no remarkable changes with respect to optical and electronic features of the pure MgO after interactions. Consequently, the Al substitutions with Mg atoms placed in the middle and end sites have shown significant changes in values of the frontier molecular orbital space distribution and ground state dipole moment of states V and VII after interaction with hydrazine compared to those of hydrazine adsorbed onto pure MgO nanotubes. The quantum molecular descriptor and TD-DFT calculations show that electrons transfer from the HOMO orbitals of Al-defected MgO nanotubes to LUMO, LUMO-1 and LUMO-2 orbitals of hydrazine. This study indicates for sensor applications that Al-defected-MgO nanotubes (states X and Z) are more likely to facilitate the hydrazine detection compared to pure MgO nanotubes.