Nitrogen-doped titanium dioxide visible light photocatalyst: Spectroscopic identification of photoactive centers
The nitridation of TiO 2 by NH 3-generated substitutional N species with a diamagnetic [O–Ti 4+–N 3−–Ti 4+] core stabilized by a neighboring oxygen vacancy that can work under visible light. This paper focuses on the photoactive centers of nitrogen-doped TiO 2 visible light photocatalyst. A series o...
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Veröffentlicht in: | Journal of catalysis 2010-12, Vol.276 (2), p.201-214 |
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Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The nitridation of TiO
2 by NH
3-generated substitutional N species with a diamagnetic [O–Ti
4+–N
3−–Ti
4+] core stabilized by a neighboring oxygen vacancy that can work under visible light.
This paper focuses on the photoactive centers of nitrogen-doped TiO
2 visible light photocatalyst. A series of N-doped TiO
2 materials were prepared by a post-nitridation route at the temperature range of 400–800
°C. The photocatalytic oxidation of acetone as a model reaction was used to evaluate the photocatalytic properties of the materials. The chemical states of doped nitrogen species were characterized by near-edge X-ray absorption fine structure, X-ray photoelectron, and electron paramagnetic resonance spectroscopies. The results reveal that four types of N species exist alone or together in TiO
2 depending on nitridation temperature. The photoactive centers of the materials are a diamagnetic [O–Ti
4+–N
3−–Ti
4+–
V
0
-
] cluster containing an oxygen vacancy and a nitrogen anion. The visible light photocatalysis of N-doped TiO
2 is proposed to be initiated by an excited state of the surface [Ti
4+–N
3−] unit. |
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ISSN: | 0021-9517 1090-2694 |
DOI: | 10.1016/j.jcat.2010.07.033 |