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Photochemical Properties, Composition, and Structure in Molecular Beam Epitaxy Grown Fe "Doped" and (Fe,N) Codoped Rutile TiO2(110)
被引:28
作者:
Mangham, Andrew N.
[1
]
Govind, Niranjan
[1
]
Bowden, Mark E.
[1
]
Shutthanandan, V.
[1
]
Joly, Alan G.
[1
]
Henderson, Michael A.
[1
]
Chambers, Scott A.
[1
]
机构:
[1] Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, Richland, WA 99352 USA
关键词:
PHOTOINDUCED REDOX REACTION;
QUANTUM-SIZED TIO2;
METAL-ION DOPANTS;
ELECTRONIC-STRUCTURE;
TITANIUM-DIOXIDE;
ULTRASOFT PSEUDOPOTENTIALS;
PHOTOCATALYTIC ACTIVITY;
TRIMETHYL ACETATE;
N INCORPORATION;
SURFACE;
D O I:
10.1021/jp203061n
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
We have investigated the surface photochemical properties of Fe "doped" and (Fe,N) codoped homoepitaxial rutile TiO2(110) films grown by plasma-assisted molecular beam epitaxy. Fe does not incorporate as an electronic dopant in the rutile lattice but rather segregates to the film surface. However, codeposition of Fe with N enhances the solubility of Fe, and DFT calculations suggest that codopant complex formation is the driving force behind the enhanced solubility. The codoped films, in which a few atomic percent of Ti (O) are replaced with Fe (N), exhibit significant disorder compared to undoped films grown under the same conditions, presumably due to dopant-induced strain. Codoping redshifts the rutile bandgap into the visible. However, the film surfaces are photochemically inert with respect to hole-mediated decomposition of adsorbed trimethyl acetate. The absence of photochemical activity may result from dopant-induced trap and/or recombination sites within the film. This study indicates that enhanced visible light absorptivity in TiO2 does not necessarily result in visible light initiated surface photochemistry.
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页码:15416 / 15424
页数:9
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