Metastable Structure of Photoexcited WO3Determined by the Pump-probe Extended X-ray Absorption Fine Structure Spectroscopy and Constrained Thorough Search Analysis

The local structure of WO3photocatalyst in the photoexcited metastable state created 150 ps after laser irradiation have been determined by pump-probe L3-edge EXAFS and constrained thorough search analysis. A highly distorted octahedral local structure was found where one of the shortest W-O bonds was further shortened to 1.66 Å while the other five bonds were rather elongated even though theoretical calculations predicted the reverse change. We discuss this contradiction and propose a possible structure for the metastable state.The local structure of WO3photocatalyst in the photoexcited metastable state created 150 ps after laser irradiation has been determined by pump-probe EXAFS and constrained thorough search analysis. A highly distorted octahedral local structure was found, especially one of the shortest W-O was further shortened. We discuss contradiction with theoretical calculation and propose a possible structure for the metastable state.