Synthesis of TiO2 nanoparticles on the Au(111) surface

Jürgen Biener; Enrique Farfan-Arribas; Monika Biener; Cynthia M Friend; Robert J Madix

doi:10.1063/1.1999607

Synthesis of TiO2 nanoparticles on the Au(111) surface

J Chem Phys. 2005 Sep 1;123(9):94705. doi: 10.1063/1.1999607.

Authors

Jürgen Biener¹, Enrique Farfan-Arribas, Monika Biener, Cynthia M Friend, Robert J Madix

Affiliation

¹ Department of Chemistry and Division of Engineering and Applied Sciences, Harvard University, Oxford Street, Cambridge, Massachusetts 02138, USA.

PMID: 16164360
DOI: 10.1063/1.1999607

Abstract

The growth of titanium oxide nanoparticles on reconstructed Au(111) was investigated by scanning tunneling microscopy and x-ray photoelectron spectroscopy. Ti was deposited by physical-vapor deposition at 300 K. Regular arrays of titanium nanoparticles form by preferential nucleation of Ti at the elbow sites of the herringbone reconstruction. The titanium oxide nanoclusters were synthesized by subsequent exposure to O(2) at 300 K. Two-and three-dimensional titanium oxide nanocrystallites form during annealing in the temperature range from 600 to 900 K. At the same time, the Au(111) surface assumes a serrated 110-oriented step-edge morphology suggesting step-edge pinning by titanium oxide nanoparticles. The oxidation state of the titanium oxide nanoparticles varies with annealing temperature. Specifically, annealing to 900 K results in the formation of stoichiometric TiO(2) nanocrystals as judged by the Ti(2p) binding energies measured in the x-ray photoelectron data. The nanodispersed TiO(2) on Au(111) is an ideal system to test the various models proposed for the enhanced catalytic reactivity of supported Au nanoparticles.