| Project/Area Number |
17560592
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | The University of Electro-Communications |
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Principal Investigator |
TANAKA Katsumi The University of Electro-Communications, Department of Electronic Engineering, Professor (30155121)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Titania nanoparticles / Pulsed Laser Ablation / PLA in Water / ICP-Mass / Visible Light Response / Environmental Cleaning / Quantum Size Effect / Thin Film / パルスレーザーアプレーション / 微粒子半導体 / 酸化チタン / シリコン微粒子 / 光触媒 / 半導体微粒子 / 可視光応答触媒 |
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| Research Abstract |
The amount of titanium formed by TiO2 single crystal PLA in water was measured by ICP-mass spectrometry. The PLA yield was evaluated as a function of laser fluence, water thickness, pH and temperature in solution, and acid kind. The yield was mainly controlled by the former two factors and was shown by two equations. The size and behavior of titania particles on the substrate were studied with STM. The size of the particles as small as 4nm was detected and they easily moved on the substrate surface by biased voltage between tip and nano-particles. The bandgap of the thin films was measured to be 3.87 to 4.13eV with diffused reflectance spectroscopy. Such clear bandgap enlargement due to quantum-size effect is quite unique only on these nano-particles. Such blue shift is disadvantage for the photo-catalytic reaction on TiO2. However, the thin films were photo-active to methylene blue degradation not only with ultraviolet but also with >400nm visible light. The fact was interpreted by the impurity levels formed in between the enlarged bandgap such as nitrogen involved by PTA in water. Probably high concentration of impurity in nanoparticles play significant role on producing much holes active for photo-oxidation with visible light.
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