| Project/Area Number |
13555239
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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 |
無機工業化学
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| Research Institution | Tohoku University |
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Principal Investigator |
SATO Tsugio Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Professor, 多元物質科学研究所, 教授 (90091694)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIDA Satoshi Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Research Associate, 多元物質科学研究所, 助手 (60232849)
YIN Shu Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Lecturer, 多元物質科学研究所, 講師 (40271994)
内田 聡 東北大学, 多元物質科学研究所, 助手 (18030547)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2002: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥8,300,000 (Direct Cost: ¥8,300,000)
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| Keywords | soft solution reaction / ceria nanoparticle / UV-shielding property / Transperency in the visible light region / Photocatalytic activity / Singlet oxygen / Damage to DNA / Safety to a human body / セリア / ナノ粒子 / 紫外線遮蔽能 / 白色化 / 仮焼 / 構造水 / 格子欠陥 / 酸化触媒活性 / 金属イオン固溶 |
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| Research Abstract |
Ceria nanoparticles were prepared by reacting cerium chloride aqueous solution and sodium hydroxide aqueous solution at 40℃ followed by the oxidation with hydrogen peroxide and their characteristics such as morphology, oxidation catalytic activity, photocatalytic activity, UV-shielding ability and transparency in the visible light region were investigated. The morphology of the particle greatly changed depending on the solution pH and doping metal ion. Namely, the product at pH 12 and 6 consisted of rod-like particles and spherical particles, respectively. The crystallite size greatly reduced by doping with calcium ion and zinc ion. The oxidation catalytic activity also greatly decreased by doping with divalent anions. Especially, calcium ion and zinc ion were effective to reduce the oxidation catalytic activity. Both undoped ceria and doped ceria showed much lower photocatalytic activity than titania and zinc oxide. The UV-shielding ability and transparency in the visible light region of ceria nanoparticle were improved by doping with calcium ion and zinc ion. Generally, ceria is yellow, but white powder of ceria possessing excellent UV-shielding ability and transparency in the visible light region could be obtained by calcining nanoparticles of calcia-doped ceria. Titania and zinc oxide caused damages to DNA under irradiation of UV light, but the damages to DNA with undoped ceria and calcium and zinc ion doped ceria were the same level with blank test without Sample. The generation of singlest oxygen under UV irradiation determined by chemical luminescence assay was in the order zinc oxide > titania >> undoped ceria > calcium ion doped ceria = zin ion doped ceria. According to these results, it may be concluded that calcium ion doped ceria can be used as a new UV-absorbent which is excellent in the Safety to a human body.
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