2005 Fiscal Year Final Research Report Summary
Development of Highly Visible-light Sensitive Photocatalyst by Controlling Surface Nano-structure of TiO_2 with Cold Plasma Treatments
| Project/Area Number |
15360394
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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 | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Kitakyushu National College of Technology |
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Principal Investigator |
YAMADA Kenji Kitakyushu National College of Technology, Department of Materials Science and Chemical Engineering, Professor, 物質化学工学科, 教授 (80101179)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Hiroyuki Kitakyushu National College of Technology, Integrated Arts and Science, Professor, 総合科学科, 教授 (70172434)
MATSUSHIMA Shigenori Kitakyushu National College of Technology, Department of Materials Science and Chemical Engineering, Professor, 総合科学科, 教授 (80229476)
YAMANE Hirokazu Kitakyushu National College of Technology, Department of Materials Science and Chemical Engineering, Professor, 総合科学科, 助教授 (70332096)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Materials Processing and Treatment / Plasma Processing / Surface and Interface Properties / Structural and Function Materials / Nano-materials / Catalytic and Chemical Processes |
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| Research Abstract |
A film composed of TiO_2 particles was treated with argon and nitrogen plasmas, in series, with magnetron-type cold plasma reactor. According to XRD analysis, half-value width of anatase (101) plane was increased with nitrogen-doping and it becomes apparent that crystal lattice of anatase was distorted with nitrogen-doping. Such lattice distortion will be originated with formations of Ti-N bonds and oxygen defects.
The plasma-treated film revealed visible-light absorption, in addition to ultraviolet-light absorption. Visible-light activity appeared, corresponding to the visible-light absorption. The appearance of the visible-light activity will be originated by the formation of Ti-N bonds. According to theoretical analysis of band structure for the nitrogen-doped TiO_2, the formation of Ti-N bonds will be adequate for narrowing of the band gap in the visible-light active TiO_2. Optimum content of Ti-N bonds is necessary to obtain the highest visible-light activity. A large excess of Ti-N bonds will bring about an increase in oxygen defects which depress the visible-light activity of the particles.
In this work, it becomes apparent that surface nano-structure of TiO_2 particles can be controlled by the cold plasma treatments. It is possible by the cold plasma treatments to accelerate the formation of Ti-N bonds and depress the formation of the oxygen defects in the particles, and highly sensitive photocatalyst can be developed by the appearance of the visible-light activity in the particles.
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