Xihan Chen* and Tanja Cuk
J. Phys. Chem. C听2021, 125, 33, 18204, DOI:听
Water oxidation is considered as one of the most important reactions in solar-to-fuel generation. The initial catalytic intermediates formed on an ultrafast timescale play a great role in controlling water oxidation reaction. Here, we use ultrafast听in situ听infrared attenuated total reflectance spectroscopy to study the initial water oxidation intermediates at a state-of-the-art TiO2听P25/aqueous interface. We observe a Ti鈥揙 vibration near 850 cm鈥�1听possibly in the anatase phase, suggested to be a subsurface vibration as a result of hole localization on the P25 surfaces. Such a subsurface Ti鈥揙 vibration is found to couple to reactant dynamics (water librations). This experiment suggests that a subsurface vibration could be a distinctive infrared reporter of reaction intermediates for water oxidation on titania surfaces.