Photocatalytic Activity Of TiO2 Thin Films Research Articles

Characteristics and Photocatalytic Properties of Thin Film Prepared by Sputter Deposition and Post-N+Ion Implantation

TiO2thin films of a rutile, an anatase, and a mixture type with anatase and rutile were fabricated by a magnetron sputtering method. The fabricated films were irradiated by N+ions with several doses using the Freeman ion source. Atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-VIS spectrophotometer were employed to investigate morphology, structure, chemical state, and optical characteristics, respectively. Photocatalytic activity was evaluated by degradation of a methylene blue solution using UV and visible light. TiO2thin films with each structure irradiated by N+ions showed the different N concentration in the same N+ion dose and the chemical state of XPS results suggested that an O atom in TiO2lattice replaced by an N atom. Therefore the photocatalytic activity of TiO2thin films was improved under visible light. The maximum photocatalytic activity of TiO2thin films with each structure was indicated at N concentration of 2.1% for a rutile type, of 1.0% for an anatase type, and of 3.8% for a mixture type under the condition of ions/cm2in N+ion dose.

Effects of Fe-Doping on the Structures and Photocatalytic Activities of TiO2 Thin Films

The Fe-doped TiO2 films were prepared by sol-gel method and characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),confocal microscope Raman spectrometer(Raman),UV-Vis absorption spectroscopy(UV-Vis) and atomic force microscopy(AFM).The photocatalytic activities of the films were evaluated by using the degradation of the methyl orange.The results showed that TiO2 in Fe/TiO2 films took an anatase structure when calcinated between 300 ℃ and 600 ℃.Increasing the calcination temperature up to 700 ℃,TiO2 transformed to rutile phase.The roughness and the grain size of Fe/TiO2 films grew gradually with the increases of the doping amount of Fe content and the calcination temperature.The photon excited wavelength of the Fe/TiO2 films moved to the visible light gradually with the increase of number of coating layer.Low levels of Fe-doping improved the photocatalytic activities of the TiO2 thin films,while higher doping decreased the photocatalytic activities of TiO2 thin films.The optimal Fe-doping was found to be 0.1% for the maximum degradation of methyl orange.

Photocatalytic Activity of Ag<sup>+</sup>-Doped TiO<sub>2</sub> Thin Films Prepared by Sol-Gel Method

TiO2and Ag+-doped TiO2thin films were successfully obtained on microscope glass slides by means of sol-gel method. Then the photocatalytic activity of the TiO2and Ag+-doped TiO2thin films was evaluated by the degradation of rhodamine B dye solution. The effects of both annealing temperatures and Ag+contents on the photocatalytic activity of TiO2thin films were examined. The results indicated that the TiO2thin films with an atomic ratio of Ti:Ag=10:1 annealed at 300°C had a higher photocatalytic activity.

Electrical Property of TiO<sub>2</sub> Thin Film Deposited by RF Sputtering

The authors investigated on the electrical property and the photo-catalytic activity of TiO2 thin films deposited in Ar+O2 atmosphere by RF magnetron sputtering. From the result of x-ray diffraction, the anatase phase was formed in TiO2 thin films. In TiO2 thin film deposited under a gas pressure of 3.0Pa, the contact angle of water showed 9 ﾟ, and the decomposition rate of Methylene Blue (measuring the absorbance of the reference light) showed -0.067 with UV light irradiation. Moreover, it revealed that the electric resistivity of TiO2 thin film deposited under the same conditions decreased from 8.0×103Ω･m to 1.4×10-2Ω･m with UV light irradiation.

Photocatalytic activities of TiO2 thinfilms prepared using sputtering

Photocatalytic activities of TiO2 thinfilms prepared using sputtering