| Project/Area Number |
10555213
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
OHTANI Bunsho Hokkaido Univ., Catalysis Research Center, Pro., 触媒化学研究センター, 教授 (80176924)
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| Co-Investigator(Kenkyū-buntansha) |
UOSAKI Kohei Hokkaido Univ., Grad. School of Sci., Pro., 大学院・理学研究科, 教授 (20133697)
KOMINAMI Hiroshi Kinki Univ., Fac.Sci.Eng., Lec., 理工学部, 講師 (00257966)
IKEDA Shigeru Hokkaido Univ., Catalysis Research Center, Inst., 触媒化学研究センター, 助手 (40312417)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥9,200,000 (Direct Cost: ¥9,200,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1999: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1998: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Keywords | Semiconductor Suspension / Photocatalysis / Ultrafast Laser / Titanium Dioxide / Anatase / Rutile / Electron-hole recombination / Recombination Rate Constant / 光触媒活性 / ポンプ-プローブ法 |
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| Research Abstract |
This study aimed at rationalization of the hypothesis that the most decisive factors controlling the photocatalytic activity of semiconductor powders is surface area and crystallinity. The larger the surface area becomes, the more the reaction substrate molecules are adsorbed on the surface, to result in the higher activity, while the higher the crystallinity of particles, the smaller the crystal defect inducing electron-hole recombination. Therefore it is expected that semiconductor particles having large surface area and being high crystallinity should exhibit high photocatalytic activity. We have developed the novel method of titanium (IV) oxide preparation without the use of water ; (1) Hydrothermal Crystallization of Organic Media (HyCOM), (2) Thermal Decomposition (TD), and (3) Transfer Hydrolytic Crystallization in Alcohols (THyCA). The titanium (IV) oxide powders thus prepared had large surface area and high crystallinity of anatase crystallites. As expected from these physical properties, these powders showed the photocatalytic activity, under both aerated and deaerated conditions which is marked higher than that of highly active commercially available titanium (IV) oxide (Degussa P-25). Thus, we have confirmed the principle for the design of ultra-highly semiconductor photocatalyst and developed the novel synthetic methods. By using femtosecond laser systems, the reduced rate of electron-hole recombination was clarified.
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