Photoinduced desorption of O2 and photooxidation of organics from TiO2(110) surfaces

PHYS 385

David Sporleder, dsporled@bnl.gov1, Daniel P. Wilson1, and Michael G. White, mgwhite@bnl.gov2. (1) Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, (2) Chemistry Department, Brookhaven National Lab and Stony Brook University, Stony Brook, NY 11794
We present here, a study of photoinduced O2 desorption from, and reaction with coadsorbates on, a single crystal rutile TiO2(110) surface. Translational energy distributions of O2 photodesorbed with a photon excitation energy between 3.5 and 4.2 eV were measured using a pump-probe, time-of-flight (TOF) method. This method utilized a one-photon VUV ionization scheme for product detection that was developed in our lab. The translational energy distribution was found to be trimodal, indicating that different O2 species (i.e. O2- or O22-) or binding sites play a role. It was found that the O2 translational energy distributions did not depend on the excitation energy over the range studied, which is consistent with a substrate mediated excitation mechanism. More recent experiments are exploring the mechanism for photooxidation of organic molecules. Specifically, we are determining translational energy distributions of small radicals originating from photoinduced fragmentation of simple ketones on a TiO2(110) surface.
 

PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008