2006 Fiscal Year Final Research Report Summary
High efficient charges separation-type photo-electrode with controlled energy band-bending
| Project/Area Number |
16206075
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | Osaka University |
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Principal Investigator |
MATSUO Shinya Osaka University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (90029299)
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| Co-Investigator(Kenkyū-buntansha) |
OMATA Takahisa Osaka University, Graduate School of Engineering, Associate Professor, 大学院工学研究科, 助教授 (80267640)
UEDA Masato Osaka University, Graduate School of Engineering, Research Associate, 大学院工学研究科, 助手 (40362660)
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| Project Period (FY) |
2004 – 2006
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| Keywords | photo-electrode / dye-sensitized solar cell / titanates / titanium oxide / charge separation / water splitting |
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| Research Abstract |
An energy band-bending induced by homo-and hetero-junctions of semiconductors must be a key factor for attainment of efficient hydrogen production via photo-electrode water splitting. In the present study, composites of TiO_2 with donor-doped titanate, Sr(Ti_<1x>Nb_x)O_<3+5> in states of powder, single crystal and thin film, were prepared, and various pysico-chemical phenomena, i.e., photo-bleaching of dyes, water splitting photo-reaction, dye-sensitized photo-current, and ions adsorption, were investigated. (1) Photobleaching of methylene blue aqueous solution sensitized with Sr(Ti_<1-x>Nb_x)O_<3+δ>/ TiO_2 composite powders proceeded several time faster than that with TiO_2 alone. Strong adsorption of MB on the powder was observed. This revealed spatial separation of photo-excited charges near the junction. (2) When Sr(Ti_<0.98>Nb_<0.02>)O_<3+δ> single crystal plate covered by TiO_2 thin film was used as a photo-electrode, the photo-current was larger 1.5 or 2 times than that for glass plate with FTO thin film covered by TiO_2 thin film. The TiO_2 thin film was prepared by sol-gel method. (When mono-light was irradiated, on-set wavelength for Sr(Ti_<0.98>Nb_<0.02>)O_<3+δ> single crystal / TiO_2 was shifted toward shorter wavelength 20 nm (0.1 eV) than that for FTO glass plate / TiO_2. (3)This proved the existence of spike in the heterojunction, end therefore this confirms the appearance of band-bending due to heterjunction. (4)The preparation of Sr(Ti_<i-x>Nb_5)O_<3+5>/ TiO_2 junction on the Ti-based alloy plates and controlling of ion adsorption on the composite powder were examined. (5) The controlling of the ion species adsorbed on the electrode must become important for photo-electrochemical reaction. The findings described above should be applied for highly efficient photo-electrochemical water splitting
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Research Products
(4 results)
