مشخصات پژوهش

Comparison of structural and electronic properties between pristine and N-doped titanium dioxide-(TiO2)/molybdenum disul¯de (MoS2) nanocomposites and their e®ects on the adsorption of thiophene molecule were performed using density functional theory calculations. To correctly estimate the adsorption energies, the van der Waals interactions were taken into account in the calculations. On the TiO2/MoS2nanocomposite, thiophene molecule tends to be strongly adsorbed by its sulfur atom. The ¯ve-fold coordinated titanium atom of TiO2was found to be an active binding site for thiophene adsorption. The results suggest that the thiophene molecule has not any mutual interaction with MoS2 nanosheet. The electronic structures of the complex systems are discussed in terms of the density of states and molecular orbitals of the thiophene molecules adsorbed to the TiO2/MoS2nanocomposites. It was also found that the doping of nitrogen atom is conductive to the interaction of thiophene with nanocomposite. Thus, it can be concluded that the interaction of thiophene with N-doped TiO2/MoS2 nanocomposite is more energetically favorable than the interaction with undoped nanocomposite. The sensing capability of TiO2/MoS2toward thiophene detection was greatly increased upon nitrogen doping. These processes ultimately lead to the strong adsorption of thiophene on the N-doped TiO2/ MoS2nanocomposites, indicating potential applicability of these nanocomposites as novel gas sensors.