The Preparation And The Characteristics Of Titanium Oxide Films And Carbon-Doped Ones

l)Nanoscale TiO₂ thin films were successfully fabricated by R.F. magnetron sputtering and arc ion plating on glass substrates. With the help of XRD,AFM,UV-Vis and the experiments of hydrophilicity and photocatalyty, the specific study of characteristic comparison of the films fabricated by R.F. magnetron sputtering and arc ion plating has been carried out. It has been found that the film growing rate of magnetron sputtering is lower than that of arc ion plating and that the films prepared by magnetron sputtering need much lower annealed temperature to get excellent anatase crystal than that of the films prepared by arc ion plating. The films prepared by magnetron sputtering show stronger UV absorption, though two absorptions are very close, and bigger surface area with acicular crystal. Besides, the films prepared by magnetron sputtering possess more excellent photocatalytic activity of the photodegradation to phenol and super-hydrophilicity with the contact angle back to 1° after preserved in the dark for 5 hours.After the films prepared by R.F.magnetron were annealed at different temperatures, it can be found that the film surface, annealed at 300℃, is discrete circular grain and owns abundance holes. The temperature at which the amorphous structure changes to anatase is between 300℃ and 400℃. But the image of AFM shows that the film surface ,annealed at 400℃, is symmetrical compact and successive. When the annealed temperature reaches 500℃, the anatase structure becomes more perfect than the annealed temperature of 400℃ and more obvious property of (101) preferred orientation. However, the surface becomes less symmetrical and more surface defects. There is no obvious structure difference when the films are sputtered at different oxygen partial pressures. As a whole, when the pressure ratio of argon and oxygen is 7:3 the anatase structure behaves a bit better.2) Carbon-doped TiO₂ films were prepared by R.F. magnetron sputtering from a titania target in a pure CO₂ plasma in low temperature condition. The structure and properties of the films were characterized with several measurements. The anatase crystal TiO_2-xC_x films are indicated by the X-ray Diffraction Spectras .The XRD also identifies that the C axis of TiO_2-xC_x films is prolonged and the crystal size is enlarged. The UV-VIS measurements show that the light response region of the TiO_2-xC_x films is extended to the visible light region(425nm) compared with 380nm of the pure TiO₂ sample. Meanwhile, a shoulder to the visible light region is observed. The XPS analysis of TiO_2-xC_x films indicates a significant peak of the binding energy of Ti-C through the entire depth of the film up to the matrix boundary. There is, however, no significant peak of the binding energy of Ti-C in the XPS analysis for TiO₂ films .That is to say that some of the doped carbon is inside TiO_2-xC_x films in compound. The grain size of the film is nanosized, and the two-dimensional of AFM image exhibits bigger surface area with symmetrical nanosized grain. Columnar crystal inside of the films is reavealed by SEM image. The TiO_2-xC_x films have the same photocatalysist with the TiO₂ films under UV radiation, but when they are under the visible light illumination, the Carbon-doped TiO₂ films have stronger visible light activity than the TiO₂ ones. The water contact angle reduce to about 3°and 0° upon exposure 5 and 30 minutes to visible light, respectively, while TiO₂ films reaches 12° upon exposure 5 minutes and need 45minutes to reach 0°.Therefore, the visible light induced hydrophilicity of TiO_2-xC_x films is better than that of TiO₂ films.