AVS 52nd International Symposium
    Surface Science Wednesday Sessions
       Session SS2-WeA

Paper SS2-WeA8
Reactive-Layer-Assisted Deposition (RLAD) of TiO@sub 2@ Nanoparticles on Au(111) Studied by STM and XPS

Wednesday, November 2, 2005, 4:20 pm, Room 203

Session: Reactions on Nanoclusters
Presenter: Z. Song, Columbia University
Authors: Z. Song, Columbia University
J. Hrbek, Brookhaven National Laboratory
R.M. Osgood, Columbia University
Correspondent: Click to Email
TiO@sub 2@ nanoparticles have been prepared by reactive-layer-assisted deposition (RLAD), in which Ti atoms are initially deposited on a multilayer of H@sub 2@O (or NO@sub 2@) grown on a Au(111) substrate at temperature <100 K. The chemical, structural and electronic properties of these oxide nanoparticles were studied by XPS, STM and STS. Specifically, ~1nm diameter TiO@sub 2@ particles formed with an H@sub 2@O reactive layer were obtained after raising the substrate temperature to 300K. Use of NO@sub 2@ reactive layers yields TiO@sub 2@ nanoparticles (~1nm at 300K) with NO@sub 3@ radicals decorating their surfaces at temperatures bellow 500K. Further annealing induces the desorption of N-containing species and leaves behind flat TiO@sub 2@ rutile and anatase particles (~5nm after being annealed to 700K) with various facets. STS studies showed different electronic structures for different TiO@sub 2@ particle sizes. This UHV compatible method for preparing well-defined TiO@sub 2@ nanoparticles can be used in molecular-level studies of reaction mechanisms of photocatalytic processes on TiO@sub 2@ nanoparticle surfaces.