Article ID Journal Published Year Pages File Type
1471567 Corrosion Science 2008 7 Pages PDF
Abstract

Cerium oxide based films on carbon steel were deposited using a cathodic electrodeposition approach and from relatively concentrated solutions. The effects of the relatively high cerium nitrate concentrations (0.1 and 0.25 M) and of applied current density (0.25 mA cm−2 ⩽ j ⩽ 3 mA cm−2) on the composition and microstructure of the films were thoroughly investigated with the support of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman and Fourier transformed infrared (FTIR) spectroscopies. The results showed that the use of 0.25 M solutions brought about immediate formation of the films compared to the 0.1 M. As the applied current density was increased, the time elapsed for achieving a stabilisation of the potential decreased. Also, the CeO2 crystallite size decreased with increasing applied current density. However, at high cathodic current densities, the crystallite size was similar regardless of the concentration, hence suggesting that the precipitation mechanisms became predominant. CeO2 was the major species deposited on carbon steel. Ce(OH)3 was also well distinguished in the deposits elaborated from 0.25 M solutions. Both concentrations led to the formation of a carbonated green rust in which some carbonates were probably replaced by nitrate anions. The mechanisms of formation of the green rust and its evolution with time are also elucidated in this work.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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