Papers by Keyword: Titanium Dioxide Film

Abstract: Titanium (Ti) is one of the most widely used for biomaterials, because of its excellent anti-corrosion and high mechanical properties. In addion to these properies, the bioactivity of Ti is required. Recently, coating of the titanium dioxide (TiO₂) film on Ti plate surface is useful methods to obtain biocompatibility of Ti plate. If periodic nanostructures were formed on the film surface, direction of cell spreading might be controlled due to grooves direction. Then, femtosecond laser is one of the useful tools of periodic nanostructures formation. Peiriod of periodic nanostructures might be varied by changing the laser wavelength. In the experiments, the film was formed on Ti plate with an aerosol beam which was composed of submicron size TiO₂ particles and helium gas. The film was irradiated with the femtosecond laser. Laser wavelengths of the laser was at 1044, 775 and 388 nm, respectively. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film by femtosecond laser irradiation at 1044, 775 and 388 nm, respectively. The period of the periodic nanostructures on the film produced by femtosecond laser irradiation at 1044, 775 and 388 nm was about 350, 230 and 130 nm, respectively. In the cell test, cell spreading along the grooves of the periodic nanostructures was observed although it was not done for the film without the periodic nanostructures. These results suggested that direction of cell spreading could be controlled by the periodic nanostructures formation

Abstract: In this study, we aimed at exploring a layer of radio frequency (RF) sputtered titanium dioxide (TiO₂) film on a sputtered ZnO film treated by hydrothermal reaction and then conducted characterization of the film. The main objective was to discuss characteristics of the fabricated TiO₂ films under conditions of different annealing temperature, film thickness, and oxygen flow rate. After measurement of four-point probe for the fabricated TiO₂ films under the same film thickness or oxygen flow rate, their sheet resistance all became smaller through high-temperature annealing at 500°C, and the thicker the TiO₂ film was, the higher the sheet resistance was. Under conditions of fixed TiO₂ film thickness and annealing temperature, with increasing oxygen flow rate, the sheet resistances of sample thin films increased initially and then decreased. The sheet resistances became highest at oxygen flow rate of 4 sccm. Results, measured from field emission scanning electron microscope (FE-SEM), showed that the structure arrangement of TiO₂ nanorods was affected by TiO₂ film thickness, oxygen flow rate and annealing temperature. The stacking and blending situations between nanorods became severer for higher oxygen flow rate and annealing temperature above 400°C. In addition, grains formed on film surface apparently spread more outwards as the film became thicker.

Abstract: Narrow range of visible light response and low photo-quantum are the “bottleneck” for the development of Titanium dioxide film. Doping with other ions can improve the absorption rate of visible light and improve the TiO2 photocatalytic activity by reducing the band gap of TiO2 effectively and changing the electron-hole recombination rate. The recent progress of photocatalytic performance of ions-doped TiO2 films is reviewed in this paper. Finally, the current existing problems are also presented.

Abstract: Titanium dioxide sol solution was prepared using titanium tetra-isopropoxide, urea, 2-methoxyethanol. After that, ultraviolet light was irradiated to the sol solution, then, H2O was added to the solution. The prepared sol solution was dip-coated onto fused silica plates. The as-prepared films were dried at 100 °C and then annealed at 650 °C. The annealed films were anatase type titanium dioxides. Visible light absorption by the films was observed in wavelengths longer than 380 nm. Also, photodegradation of methylene blue by visible light irradiation was accelerated in the presence of the films prepared by these methods.

Abstract: Two types of titanium dioxide sol solutions were prepared using titanium tetra-isopropoxide, urea, 2-methoxyethanol and water. The prepared sol solutions were dip-coated onto fused silica plates. These as-prepared films were dried at 100 °C and then annealed at 650 °C. The annealed films were anatase type titanium dioxides. Visible light absorption by the films was observed in wavelengths longer than 400 nm. Also, photodegradation of methylene blue by visible light irradiation was accelerated in the presence of the films prepared by these methods.

Abstract: Titanium dioxide (TiO2) films were prepared on quartz substrates by using Ti(O-i-C3H7)2(dpm)2 and O2 gas. The crystal structure, morphology and deposition rate of TiO2 films were investigated by changing deposition temperatures (Tdep) from 700 to 1100 K and total pressures (Ptot) from 0.6 to 1.0 kPa. The structure changed mainly with deposition temperature. Rutile TiO2 films with (200) orientation and anatase TiO2 films with (004) orientation both in a single phase were obtained at Tdep = 873 K and 723 K, respectively. At Tdep > 873 K, the TiO2 films had a columnar microstructure consisting of mainly anatase and a small amount of rutile. At Tdep = 723 to 873 K, the TiO2 films were the mixture of non-oriented rutile and slightly (004) oriented anatase having dense and fine-grain microstructure. The deposition rate of TiO2 films increased with increasing Tdep showing the maximum of 30 µm h-1 at Tdep = 973 K and Ptot = 0.6 kPa.