AVS 58th Annual International Symposium and Exhibition
    Surface Science Division Thursday Sessions
       Session SS-ThM

Paper SS-ThM9
Properties of TiO2 Nanoparticle Arrays Functionalized with Pt Photodeposition

Thursday, November 3, 2011, 10:40 am, Room 107

Session: Oxide Surface Structure & Reactivity
Presenter: Yu Liu, University of California, Irvine
Authors: Y. Liu, University of California, Irvine
J. Taing, University of California, Irvine
M. Cheng, University of California, Irvine
H. Bluhm, Lawrence Berkeley National Laboratory
J.C. Hemminger, University of California, Irvine
Correspondent: Click to Email
Titanium(IV) oxide (TiO2), acting as a stable support for photocatalysts and sensitizers, has applications in catalysis and energy science. Metal nanoparticles supported on TiO2 have been shown to have unusual reactivity. The deposition of metal nanoparticles can alter the electronic properties of the TiO2 nanoparticles. To understand the influence of metal deposition, we photodeposit platinum (Pt) onto ordered linear arrays of TiO2 nanoparticles grown at the step edges of highly oriented pyrolytic graphite. X-ray photoelectron and absorption spectroscopies were used to explore the electronic structure of the TiO2 nanoparticle arrays with and without photodeposited Pt. The titanium L-edge spectra, supported by multiplet calculations, provide crucial information about crystal field effects, atomic multiplet interactions, and the phase of the TiO2particles. Valence photoemission results and band structure calculations using density-functional theory indicate a narrowing of the TiO2 band gap when Pt is loaded onto the TiO2 nanoparticle surface. This suggests that Pt photodeposition onto linear TiO2 nanoparticle arrays may enhance the solar absorption of TiO2 due to narrowing of the TiO2 bandgap.