- David M. Herlihy,听Matthias M. Waegele,听Xihan Chen,听C. D. Pemmaraju,听David Prendergast,听and听Tanja Cuk
- Nature Chemistry听volume8,听pages549鈥�555听(2016). DOI: 10.1038/nchem.2497. Download
Although the water oxidation cycle involves the critical step of O鈥揙 bond formation, the transition metal oxide radical thought to be the catalytic intermediate for this step has eluded direct observation. The radical represents the transformation of charge into a nascent catalytic intermediate, which lacks a newly formed bond and is therefore inherently difficult to detect. Here, using theoretical calculations and ultrafast听in situ听infrared spectroscopy of photocatalysis at an n-SrTiO3/aqueous interface, we reveal a subsurface vibration of the oxygen directly below, and uniquely generated by, the oxyl radical (Ti鈥揙鈥�). Intriguingly, this interfacial Ti鈥揙 stretch vibration, once decoupled from the lattice, couples to reactant dynamics (water librations). The
se experiments demonstrate subsurface vibrations and their coupling to solvent and electron dynamics to detect nascent catalytic intermediates at the solid鈥搇iquid interface at the molecular level. One can envision using the subsurface vibrations and their coupling across the interface to track and control catalysis dynamically.