Electrodeposition of cerium oxide films and composites

Nanostructured CeO2 films were prepared by cathodic electrolytic deposition (ELD) and electrophoretic deposition (EPD). Benzoic acid has been utilized for the dispersion and charging of CeO2 nanoparticles for EPD. The kinetics of ELD and EPD was investigated. Electrodeposition method has been developed for the deposition of poly(2-vinylpyridine) (PVP) films. The thickness of the films was varied in the range of 0.1–3 μm. The deposition mechanism was based on the pH increase in the cathodic reactions, electrophoresis of the protonated PVP macromolecules, neutralization of their charge and film formation at the cathode surface. The deposition yield was studied by the quartz crystal microbalance method. Two electrochemical strategies were developed for the fabrication of composite PVP-CeO2 films, which were based on the electrodeposition of PVP and ELD or EPD of CeO2. The composite films were studied by electron microscopy, X-ray diffraction, thermogravimetric and differential thermal analysis. The CeO2 content in the composite films was varied by the variation of bath composition. The deposition methods allowed the fabrication of crack-free PVP-CeO2 films, which provided corrosion protection of stainless steel substrates in aqueous NaCl solutions.