2017年7月
Femtosecond time-resolved X-ray absorption spectroscopy of anatase TiO2 nanoparticles using XFEL
STRUCTURAL DYNAMICS
- 巻
- 4
- 号
- 4
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1063/1.4989862
- 出版者・発行元
- AMER INST PHYSICS
The charge-carrier dynamics of anatase TiO2 nanoparticles in an aqueous solution were studied by femtosecond time-resolved X-ray absorption spectroscopy using an X-ray free electron laser in combination with a synchronized ultraviolet femtosecond laser (268 nm). Using an arrival time monitor for the X-ray pulses, we obtained a temporal resolution of 170 fs. The transient X-ray absorption spectra revealed an ultrafast Ti K-edge shift and a subsequent growth of a pre-edge structure. The edge shift occurred in ca. 100 fs and is ascribed to reduction of Ti by localization of generated conduction band electrons into shallow traps of self-trapped polarons or deep traps at penta-coordinate Ti sites. Growth of the pre-edge feature and reduction of the above-edge peak intensity occur with similar time constants of 300-400 fs, which we assign to the structural distortion dynamics near the surface. (C) 2017 Author(s).
- リンク情報
- ID情報
-
- DOI : 10.1063/1.4989862
- ISSN : 2329-7778
- Web of Science ID : WOS:000410007200010