D644 Journal of The Electrochemical Society, 161 (12) D644-D650 (2014) 0013-4651/2014/161(12)/D644/7/$31.00 © The Electrochemical Society The Composition-Dependent Color Evolution of Anodic Electrodeposited Cerium Oxide Thin Film

Cerium oxide thin films with various colors were deposited onto 316L stainless steel using anodic electrodeposition approach. The correlation between color, composition and deposition time has been established. Results show that the film color evolves from golden yellow (1.5 h), purple (3 h), blue (5 h), gray-green (7 h) and turns back to yellow (12 h) again, and all these colored films are stable in the ambient conditions. The film color is related to both the contents of Ce(III) and hydroxide species in the films. The relative content of Ce(III) increases from 21.19 % to 27.57 % with increasing the deposition time from 1.5 h to 7 h, and then decreases to 22.93 % for the film deposited at 12 h. The content of hydroxide species shows the same variation trend as Ce(III) with the deposition time. © 2014 The Electrochemical Society. [DOI: 10.1149/2.0191412jes] All rights reserved. Manuscript submitted May 8, 2014; revised manuscript received August 4, 2014. Published August 14, 2014. Cerium oxides, particularly ceria (CeO2), have been widely applied in various areas, such as solid oxide fuel cells,1 polishing agents,2 catalysts for three-way catalysis of exhaust gas from automobiles,3 electrochromic,4 pharmacology,5 and coatings for corrosion protec-tion of metallic materials.6–12 It is well known that pure CeO2 is pale yellow probably due t