%0 Journal Article
%@ 0036-8075
%A Onda, K
%A Li, B
%A Zhao, J
%A Jordan, KD
%A Yang, J
%A Petek, H
%D 2005
%F pittir:16066
%J Science
%N 5725
%P 1154 - 1158
%T Wet electrons at the H<inf>2</inf>O/TiO<inf>2</inf>(110) surface
%U http://d-scholarship-dev.library.pitt.edu/16066/
%V 308
%X At interfaces of metal oxide and water, partially hydrated or "wet-electron" states represent the lowest energy pathway for electron transfer. We studied the photoinduced electron transfer at the H 2O/TiO2(110) interface by means of time-resolved two-photon photoemission spectroscopy and electronic structure theory. At ∼1-monolayer coverage of water on partially hydroxylated TiO2 surfaces, we found an unoccupied electronic state 2.4 electron volts above the Fermi level. Density functional theory shows this to be a wet-electron state analogous to that reported in water clusters and which is distinct from hydrated electrons observed on water-covered metal surfaces. The decay of electrons from the wet-electron state to the conduction band of TiO2 occurs in ≤15 femtoseconds.