DFT Study of Electric Field Effect on the Adsorption of Some Nitroaromatic Compounds on the Surface of Zinc Oxide Nanotube

In this research, the adsorption process of 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, tetryl and nitrobenzene on the surface of (8,0) ZnO NanoTube (NT) and the effect of the external electric field on the adsorption properties have been investigated using density functional theory. The results show that these molecules are adsorbed on the ZnO NT with adsorption energies of -61.7, -54, -110.7 and -61.7 kJ/mol, respectively. Also, the energy gap of the tube increased more than 0.5eV after adsorption process. It suggests that the adsorption of these nitroaromatic molecules can induce a significant change in the electrical conductivity of the tube, which shows the potential application of (8, 0) ZnO NT for sensing of the studied molecules. The obtained results of applying the external electric field on the adsorption process of these nitroaromatic compounds showed that the adsorption energy and the energy gap can be controlled by the engineering of electric field strength and direction.