EXAFS study of thin-film zirconium oxide deposited on a TiO2 surface

Abstract

Zirconium oxide overlayers have been prepared by deposition of Zr cations on the TiO₂ surface from a solution of zirconium butoxide in toluene. The structures of the samples thus prepared were characterized by means of EXAFS. Fourier transforms of the Zr K-edge EXAFS of a sample containing 0.245 g of Zr g^–1 TiO₂ show that the Zr cation surface species are present in an amorphous state. Curve-fitting analysis for the Zr–O shells indicates that the environment of the deposited zirconium cations is almost the same as that found in monoclinic ZrO₂. Although for high Zr samples the ZrO₂ exists as a three-dimensional monoclinic phase, as revealed by XRD, the zirconium oxide species in lower deposition samples is dispersed over titania as a two-dimensional overlayer.