Insight into the electronic and magnetic properties of TiO2 (101) surfaces with adsorbed water and ethanol molecules

摘要

The nature of adsorbates (water and ethanol) on the anatase TiO2 (101) surface has been investigated with first-principles calculations. Our results reveal that the band gap narrows by 0.2 and 0.7 eV for the water and ethanol respectively adsorbed on the perfect surface. The O-3 molecule in the system with one Ti vacancy on the surface will disappear after adsorbing. On the basis of the Bader charge analysis, water and ethanol would donate electrons to the 2p of twofold coordinated O atoms, which leads to the valence band maximum up. In addition, the disappearance of the O-3 molecule also affects the distribution of the impurity states in the band gap. Although the adsorbates affect the electronic structures and local structures of the TiO2 (101) surface, the magnitude of magnetic moments induced by the Ti vacancy hardly changes. (C) 2016 Elsevier B.V. All rights reserved.