AVS 60th International Symposium and Exhibition
    Surface Science Thursday Sessions
       Session SS+EN-ThM

Paper SS+EN-ThM9
TiO2 Nanoparticle Arrays Functionalized with Pt Photodeposition: Studies Using X-ray Spectroscopies under In Situ Heating and Hydrogen Annealing

Thursday, October 31, 2013, 10:40 am, Room 201 A

Session: Photocatalysis and Photochemistry at Surfaces
Presenter: Y. Liu, University of California, Irvine
Authors: Y. Liu, University of California, Irvine
J. Taing, University of California, Irvine
C.-C. Chen, Argonne National Laboratory
H. Bluhm, Lawrence Berkeley National Laboratory
Z. Liu, Lawrence Berkeley National Laboratory
M. Veenendaal, Argonne National Laboratory
T. Devereaux, SLAC National Accelerator Laboratory
J.C. Hemminger, University of California, Irvine
Correspondent: Click to Email

Using ambient pressure x-ray spectroscopies, we report the electronic and surface structures of TiO2 nanoparticle arrays with and without Pt photodeposition under in-situ heating and hydrogen annealing. X-ray absorption and transmission electron microscopies indicate that the TiO2 nanoparticles are in the rutile phase, but the anatase phase also can exist after Pt photodeposition. Valence photoemission results demonstrate a band gap narrowing when Pt is loaded onto the surface of TiO2 nanoparticles. Upon heating the samples, surface defects and oxygen vacancies are formed, which could prevent the recombination of electron-hole pairs. Heating also enhances the occupation of metallic Pt on top of the TiO2. In contrast, introducing hydrogen at high temperature would enhance the Pt4+ species related to the strong metal support interaction. The reduced band gap and the increased contact surface in the Pt-photodeposited TiO2 nanostructures can potentially enhance the performance of these materials in solar absorption and photocatalysis applications.

Reference:

  1. Taing, J.; Cheng, M. H.; Hemminger, J. C., Photodeposition of Ag or Pt onto TiO2 Nanoparticles Decorated on Step Edges of HOPG. ACS Nano 2011, 5, 6325-6333.
  2. Liu, Y.; Taing, J.; Chen, C.-C.; Sorini, A. P.; Cheng, M. H.; Margarella, A. M.; Bluhm, H.; Devereaux, T. P.; Hemminger, J. C., Narrowing of Band Gap in Thin Films and Linear Arrays of Ordered TiO2 Nanoparticles, to be submitted to ACS Nano.