MBE Growth and Properties of Model TiO2 Anatase Surfaces for Fundamental Studies of Heterogeneous Photocatalysis
EMSL Project ID
35094
Abstract
The overall objective of this work is to provide the field of heterogeneous photocatalysis with unique insights into the molecular-level properties of photocatalytic transformations on TiO2 anatase through joint experimental and theoretical studies of organic photooxidation reactions on model TiO2 surfaces. This EMSL proposal covers the experimental portion of the project. Heterogeneous photocatalysis on TiO2 has received considerable attention of late due to increased interest in using light to promote chemical transformations in remediation and energy technologies. Fundamental questions remain unaddressed, including reaction and charge transfer mechanisms, specific surface reaction sites, selectivity, and interplay between thermal and non-thermal processes. The vast majority of research effort has been phemonological and has provided conflicting explanations for such crucial issues as the performance differences between the polymorphs of TiO2 (rutile, anatase or mixtures thereof). In the overall project, molecular-level expertise at PNNL in material synthesis, surface chemistry, theory, photodynamics and scanning probe microscopy will be used to study three areas of fundamental importance to heterogeneous photocatalysis on TiO2. These are: (1) detailed reaction mechanisms, (2) mechanisms of charge transfer, charge trapping and energy redistribution, and (3) surface structure and material dependences, all as they relate to organic photooxidation reactions. The specific goals of this proposal focus on the molecular beam epitaxial (MBE) growth and properties model TiO2 anatase surfaces as testbeds and substrates for fundamental investigations of heterogeneous organic photooxidation reactions and the associated mechanisms. These studies are of direct relevance to DOE's mission of increasing fundamental scientific understanding of light-to-chemical energy conversions.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2009-10-05
End Date
2010-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members