Fundamental Studies of Heterogeneous Photocatalysis on Model TiO2 Surfaces
EMSL Project ID
35219
Abstract
The objective of this project is to provide the field of heterogeneous photocatalysis with unique insights into the molecular-level properties of photocatalytic transformations through joint experimental and theoretical studies of organic photooxidation reactions on model TiO2 materials. 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, e.g., reaction and charge transfer mechanisms, specific surface reaction sites, selectivity, and interplay between thermal and non-thermal processes. The vast majority of research effort in the literature has been phemonological, resulting in conflicting explanations for such crucial issues as the performance differences between the polymorphs of TiO2 (rutile, anatase or mixtures thereof). In this 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, each as they relate to organic photooxidation reactions. These issues will be explored using a variety of model TiO2 systems including single crystal surfaces and epitaxially grown films of rutile and anatase, mixed phase films of the two, and surfaces prepared with controlled structural and electronic defects and varying degrees of porosity.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2009-10-01
End Date
2011-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
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