Papers by Author: Ying Cui

Abstract: F-doped TiO2 has exhibited superior photocatalytic activity. However, its electronic structures and photocatalysis mechanism are still unclear. In the present work, the structural optimization and electronic structure of F-doped anatase TiO2 have been investigated by means of the first-principles pseudopotential total energy method. It has been demonstrated that F doping would modify the valence band at the lower energy direction in the F-doped TiO2. Calculation results confirm that doping of fluorine would not shift the absorption edge into the visible light region. Instead, we attributed its photocatalytic activity to the enhancement of the oxidative power of F-doped TiO2.

Abstract: TiO2 films were deposited by using mid-frequency twin magnetron reactive sputtering technique at ambient temperature on quartz and Si wafer. The films were annealed after deposition. The phase composition and surface morphology of the TiO2 films were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy, while the optical properties and contact angle were measured using a UV-Vis spectrophotometer and a contact angle meter. It is indicated that anatase phase dominates below 900°C and a mixture of rutile and anatase exists in the film annealed at 1000°C. Furthermore, the hydrophilic property depends on phase composition and morphological change in TiO2 films.