Chemistry Department Colloquium

"The charge-lattice coupling at a photocatalytic interface"

Presented by Professor Hrvoje Petek, University of Pittsburgh, Dept, of Physics & Astronomy

Thursday, April 3, 2008, 12:00 pm — Hamilton Seminar Room, Bldg. 555

The coupling of charge and nuclear degrees of freedom is a prerequisite for inducing photocatalytic processes at semiconductor-molecule interfaces. We explore the correlations between the structural and electronic properties of rutile TiO2(110) surface by low-temperature STM, ultrafast time-resolved photoemission spectroscopy, and first-principles theory. LT-STM measurements of reduced TiO2(110) surfaces describe the structure and excess electron distributions at O atom vacancy defect sites. DFT calculations indicate strong correlation between the lattice relaxation and the electronic structure. Time-resolved photoemission studies of H2O and CH3OH covered surfaces show the dynamical response of the interface to photoinduced charge transfer into the molecular overlayer (1-3). In particular, the dynamics of reverse charge transfer from the CH3OH overlayer show strong evidence of proton-coupled electron transfer.

Hosted by: Nick Camillone

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