Photoinduced anisotropic distortion as the electron trapping site of tungsten trioxide by ultrafast W L 1 -edge X-ray absorption spectroscopy with full potential multiple scattering calculations

Akihiro Koide (1, 2) , Yohei Uemura (2, 3) , Daiki Kido (4) , Yuki Wakisaka (4) , Satoru Takakusagi (4) , Bunsho Ohtani (4) , Yasuhiro Niwa (5) , Shunsuke Nozawa (5) , Kohei Ichiyanagi (5) , Ryo Fukaya (5) , Shin-Ichi Adachi (5) , Tetsuo Katayama (6) , Tadashi Togashi (6) , Shigeki Owada (7) , Makina Yabashi (7) , Yusaku Yamamoto (8) , Misaki Katayama (8) , Keisuke Hatada (9) , Toshihiko Yokoyama (2) , Kiyotaka Asakura (4)

1 IPR - Institut de Physique de Rennes
2 Institute for Molecular Science
3 Utrecht University [Utrecht]
4 Hokkaido University [Sapporo, Japan]
5 High energy accelerator research organization - KEK
6 JASRI - Japan Synchrotron Radiation Research Institute [Hyogo]
7 RIKEN - RIKEN - Institute of Physical and Chemical Research [Japon]
8 Ritsumeikan University
9 University of Toyama

Understanding the excited state of photocatalysts is significant to improve their activity for water splitting reaction. X-ray absorption fine structure (XAFS) spectroscopy in X-ray free electron lasers (XFEL) is a powerful method to address dynamic changes in electronic states and structures of photocatalysts in the excited state in ultrafast short time scales. The ultrafast atomic-scale local structural change in photoexcited WO3 was observed by W L1 edge XAFS spectroscopy using an XFEL. An anisotropic local distortion around the W atom could reproduce well the spectral features at a delay time of 100 ps after photoexcitation based on full potential multiple scattering calculations. The distortion involved the movement of W to shrink the shortest W–O bonds and elongate the longest one. The movement of the W atom could be explained by the filling of the dxy and dzx orbitals, which were originally located at the bottom of the conduction band with photoexcited electrons.

Domains: Chemical Sciences; Physics [physics]

Akihiro Koide, Yohei Uemura, Daiki Kido, Yuki Wakisaka, Satoru Takakusagi, et al.. Photoinduced anisotropic distortion as the electron trapping site of tungsten trioxide by ultrafast W L 1 -edge X-ray absorption spectroscopy with full potential multiple scattering calculations. Physical Chemistry Chemical Physics, 2020, 22 (5), pp.2615-2621. ⟨10.1039/C9CP01332F⟩. ⟨hal-02280133⟩