Wet electrons at the H2O/TiO2(110) surface.
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 H2O/TiO2(110) interface by means of time-resolved two-photon photoemission spectroscopy and electronic structure theory. At approximately 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.
Onda
Ken
K
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Li
Bin
B
Zhao
Jin
J
Jordan
Kenneth D
KD
Yang
Jinlong
J
Petek
Hrvoje
H