2007 Fiscal Year Final Research Report Summary
Degradation of environmental hormone by visible light active double layer photocatalyst
| Project/Area Number |
18510070
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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 |
Environmental technology/Environmental materials
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| Research Institution | University of Toyama |
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Principal Investigator |
TAKAHASHI Takakazu University of Toyama, Graduate School of Science and Engineering for Research, Associate Professor (80019223)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Photocatalyst / Titanium dioxide / Tungsten trioxide / Visible light / Sputter film / Environmental hormone / 17β-estradiol / HPLC |
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| Research Abstract |
We have prepared photocatalytic TiO_2 films by reactive DC sputtering from Ti pure metal and mixture gas of Ar+O_2. The degradation of water solution containing 17β-estradiol well known as female sex environmental hormone was performed under irradiation of UV light to the surface of TiO_2 film set up in the water solution. The concentrations of 17β-estradiol in the water solution were estimated from the measurement of HPLC in intervals during UV light was turned on. At initial stage, the degradation rate was faster with increasing UV light intensity After irradiation period was six hours, the degradation rate was saturated and independent of UV light intensity The degradation rate was different in the films deposited at different sputtering pressure. This may be due to the difference of surface area and porosity in the films.
To enhance the photocatalytic activity to visible light in solar light, we have prepared the double-layered photocatalyst composed of TiO_2 and WO_3 films. First, the WO_3 films were deposited on glass substrates by reactive sputtering. We annealed the as-deposited WO_3 films to improve the crystallinity, optical properties and surface microstructure. Then, TiO_2 films were deposited on the annealed WO_3 films by reactive sputtering. The 17β-estradiol was decomposed by the double-layered photocatalyst under irradiation of artificial solar light to the surface of TiO_2 film. The concentrations of 17β-estradiol were also estimated from HPLC, during the artificial solar light was turned on. When six hours passed after the light was turned on, the degradation rates of 17β-estradiol water solution were obtained as a values of 45% for single-layered TiO_2 films, and 57% for the double-layered photocatalyst, respectively.
These results suggest that WO_3 under layer in double-layered photocatalyst could be effectively activated for visible light and assist with the enhancement of photocatalytic activity of TiO_2 upper layer.
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[Journal Article] Visible light active nitrogen doped TiO_2 thin films prepared by DC magnetron sputtering used as a photocatalyst2008
Author(s)
K, Prabakar, T, Takahashi, K, Takahashi, T, Nakashima, Y, Kubota, A. Fujishima
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Journal Title
Renewable Energy Vol. 33
Pages: 277-281
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Effect of annealing temperature on the photocatalytic activity of sol-gel derived TiO_2 thin films2008
Author(s)
S, Biswas, Arpi, Majumder, M F, Hossain, T, Takahashi, Y, Kubota, A. Fujishima
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Journal Title
J.Vac.Sci.& Technol.A Vol. 26(in press)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Study of photocatalytic activity of TiO_2 thin films prepared in various Ar/O_2 ratio and sputtering gas pressure2007
Author(s)
S, Biswas, K, Prabakar, T, Takahashi, T, Nakashima, Y, Kubota, A. Fujishima
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Journal Title
J.Vac.Sci.& Technol.A Vol. 25, No. 4
Pages: 912-916
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Annealing effect of structural, morphological and optical properties on reactive sputtered WO_3 films for mediated heterogeneous photocatalyst2007
Author(s)
K, Prabakar, T, Takahashi, K, Takahashi, T, Nakashima, Y, Kubota, A. Fujishima
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Journal Title
J.Vac.Sci.& Technol.A Vol. 25, No. 4
Pages: 1029-1033
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Preparation and photocatalytic activity of TiO_xN_y/CdS heterojunctions2007
Author(s)
K, Prabakar, T, Takahashi, T, Nezuka, K, Takahashi, T, Nakashima, Y, Kubota, A. Fujishima
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Journal Title
J.Vac.Sci.& Technol.A Vol. 25, No. 4
Pages: 1188-1192
Description
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[Presentation] Annealing effect of structural, morphological and optical properties on reactive sputtered WO_3 films for mediated heterogeneous photocatalyst2006
Author(s)
K, Prabakar, T, Takahashi, K, Takahashi, T, Nezuka, T, Nakashima, Y, Kubota, A. Fujishima
Organizer
AVS 53rd International Symposium
Place of Presentation
San Francisco(USA)
Year and Date
20061112-17
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Preparation and photocatalytic activity of TiO_xN_y/CdS heterojunctions2006
Author(s)
K, Prabakar, T, Takahashi, T, Nezuka, K, Takahashi, T, Nakashima, Y, Kubota, A. Fujishima
Organizer
AVS 53rd International Symposium
Place of Presentation
San Francisco(USA)
Year and Date
20061112-17
Description
「研究成果報告書概要(欧文)」より
