XPS and SEM characterization of zirconia thin films prepared by electrochemical deposition

Abstract

Electrochemical deposition of zirconia on stainless steel has been investigated in order to provide supports of catalysts for NOx reduction. The zirconia films have been obtained in electrolytes based on anhydrous ethyl alcohol. The structure and chemical composition of the films have been characterized by SEM and XPS depth profiling. With rising cathodic voltage, the structure and morphology exhibit essential changes. The most porous structure corresponds to films formed at 21 V, whereas the highest density is achieved at 25 V. The XPS depth profiling data show that the composition in the bulk of the films is close to stoichiometric. The cross-section of an annealed film gives evidence for good adhesion to the substrate. The film thickness is 3–10 µm. After annealing in air at 550 °C for 1 h, no cracks and inhomogeneities are observed. Copyright © 2000 John Wiley & Sons, Ltd.