| AVS 59th Annual International Symposium and Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS-TuP |
| Session: | Surface Science Poster Session |
| Presenter: | T. Luttrell, University of South Florida |
| Authors: | T. Luttrell, University of South Florida J. Tao, University of South Florida M. Batzill, University of South Florida |
| Correspondent: | Click to Email |
A novel approach for determining the photo catalytically active surface region is presented. In this method the photo activity of well-defined epitaxial anatase and rutile TiO2 thin films is measured by methyl orange decomposition. The photo activity as a function of film thickness then enables to extract the active surface region, which is closely related to the bulk charge carrier diffusion length. Using this methodology we are able to compare differences in the photoactive region of anatase and rutile polymorphs of TiO2 as well as to investigate the effect of dopants (nitrogen and tungsten) on the depth of the active surface layer. The latter highlights the trade-off between enhanced (visible light) absorption and reduction of active volume of the photocatalyst. These studies are the first that quantifies the differences in rutile and anatase and the influence of dopants on charge carrier diffusion and thus photocatalytic activity.