Photoinduced anisotropic distortion as the electron trapping site of tungsten trioxide by ultrafast W L1-edge X-ray absorption spectroscopy with full potential multiple scattering calculations.
Akihiro KoideYohei UemuraDaiki KidoYuki WakisakaSatoru TakakusagiBunsho OhtaniYasuhiro NiwaShunsuke NozawaKohei IchiyanagiRyo FukayaShin-Ichi AdachiTetsuo KatayamaTadashi TogashiShigeki OwadaMakina YabashiYusaku YamamotoMisaki KatayamaKeisuke HatadaToshihiko YokoyamaKiyotaka AsakuraPublished in: Physical chemistry chemical physics : PCCP (2019)
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.
Keyphrases
- electron transfer
- high resolution
- density functional theory
- dual energy
- molecular dynamics
- electron microscopy
- monte carlo
- single molecule
- visible light
- molecular dynamics simulations
- mass spectrometry
- air pollution
- human health
- computed tomography
- solid state
- magnetic resonance
- risk assessment
- quantum dots
- solar cells