| AVS 56th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS2-MoM |
| Session: | TiO2 Surfaces and Interfaces |
| Presenter: | R.L. Kurtz, Louisiana State University |
| Authors: | F. Womack, Louisiana State University F. Wang, Louisiana State University Z. Zhang, Louisiana State University P. Sprunger, Louisiana State University R.L. Kurtz, Louisiana State University |
| Correspondent: | Click to Email |
Metallic nanoclusters can be buried within nanometers of the surface of TiO2 and can enhance photoabsorption to produce hot electron-hole pairs for surface chemistry. When Ag is grown on TiO2(110), STM shows that it forms ~ 5nm clusters, and HREELS shows a plasmon resonance at 3.7 eV. AFM shows that these clusters remain after coating with a thin layer of titania and conducting probe AFM shows that the conductivity in the vicinity of the clusters is enhanced consistent with their metallic nature and increased defect densities in the oxide. HREELS shows that the plasmon resonance of the nanocluster is red-shifted and broadened to 1.5-2 eV when encapsulated in titania and these findings are supported by optical measurements. The nanoclusters induce defects within the surrounding titania and the role that Ti3+ defects, O-vacancies, and Ti-interstitials play in Ag/TiO2 interactions as probed with synchrotron-based photoemission will be discussed. Electrochemical measurements have been conducted to test photochemical performance in electrolyte, and subsequent surface analysis provides information on the changes induced in morphology, defect densities, and oxidation states.
We acknowledge the support of NSF through CHE-0615606.