| Project/Area Number |
14050087
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
| Allocation Type | Single-year Grants |
|---|
| Review Section |
Science and Engineering
|
|---|
| Research Institution | Aoyama Gakuin University |
|---|
Principal Investigator |
SHIGESATO Yuzo Aoyama Gakuin University, Graduate School of Science and Technology, Professor (90270909)
|
|---|
| Project Period (FY) |
2001 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥31,100,000 (Direct Cost: ¥31,100,000)
Fiscal Year 2006: ¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 2005: ¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 2004: ¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 2003: ¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 2002: ¥6,700,000 (Direct Cost: ¥6,700,000)
|
|---|
| Keywords | Photocatalyst / Sputterig / TiO_2 / Visible Light-Active Photocatalyst / WO_3 / Photo-induced Hydrophilicity / Damages Caused by Negative Ion Bombardments / Low-impedance Sputtering / 可視光応答性 / 高速成膜 / プラズマプロセス / スマートウインドウ / スパッタリング / 防汚ガラス / 光誘起超親水性 / パルススパッタリング / 暗所維持特性 |
|---|
| Research Abstract |
TiO_2 films with the thickness of about 500nm were deposited on unheated non-alkali glass substrates by reactive magnetron sputtering using one Ti metal target with unipolar pulsed powering of 50 kHz and the plasma emission feedback system (PCU). In order to keep the very high deposition rate, the depositions were carried out in the "transition region" between the metallic and the reactive (oxide) sputter mode where the target surface was metallic and oxidized, respectively. Stable deposition was successfully carried out in the whole "transition region" with PCU at total gas pressure of 3.0 Pa. All the as-deposited films deposited in the "transition region" showed amorphous structure, which performed very low photocatalytic activity. After the post-annealing in air at higher than 300 ℃, all the films crystallized to anatase polycrystalline structure. They performed both photoinduced decomposition of acetaldehyde and photoinduced hydrophilicity under the UV light illumination. The highe
… More
st deposition rate in this study to deposit the photocatalytic TiO_2 films in the "transition region" was 90nm/min, which was over twenty times higher than that for conventional sputter deposition processes.
The WO_3 was also studied as the visible-light active photocatalyst. The WO3 films were deposited by reactive sputtering at 600 ℃ under total gas pressure of 5.0 Pa of 100 % oxygen, which performed clear photocatalytic decomposition of acetaldehyde and photo-induced hydrophilicity after visible light irradiation. The quantum yield was about 1.3 % at 440nm. The optical band gap of this film was estimated to be 2.8 eV by extrapolation of (ahv)^<1/2> plot against photon energy, wherea, h and v were absorption coefficient, Plank's constant and light frequency, respectively. Therefore, the photocatalytic reactions corresponded to inter-band transition of the electrons. These photocatalytic properties of the WO_3 films were closely related with the deposition conditions, and hence the optical band gap energy of the films. Less
|
