Valence band and catalytic activity of Au nanoparticles in Fe2O3/SiO2/Si(100) environment

Abstract

A 10-nm-thick gold film was evaporated onto a SiO2/Si(100) substrate and was implanted by Ar+ ions at 40 keV and 1015 at/cm2 dose creating island like Au nanoparticles. An 80-nm-thick gold film was also deposited the onto same substrate and considered as reference.Fe2O3 film was deposited onto the gold nanoparticles and the gold/oxide interface was modeled. The valence band and the structure were measured by means of photoelectron spectroscopy (XPS) and by transmission electron microscopy (TEM), respectively. The catalytic activity was detected by CO oxidation, which was higher after the deposition of Fe2O3 layer onto Au nanoparticles than that on a continuous Au film. This observation was correlated to the nanosize and the redistributed valence band density of states of gold in the Au/Fe2O3 interface. © 2003 Published by Elsevier B.V.