Improvement of Corrosion Resistance of TiO2 Layers in Strong Acidic Solutions by Anodizing and Thermal Oxidation Treatment
| Autor: | Yu Zuo, Xuhui Zhao, Hongchang Qian, Sahib Dino, Badar Minhas |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Anatase
Materials science Oxide chemistry.chemical_element anodized film lcsh:Technology Article Corrosion chemistry.chemical_compound General Materials Science harsh environments Ti lcsh:Microscopy lcsh:QC120-168.85 Thermal oxidation corrosion resistance lcsh:QH201-278.5 lcsh:T thermal oxidation Anodizing Titanium oxide Dielectric spectroscopy chemistry Chemical engineering lcsh:TA1-2040 lcsh:Descriptive and experimental mechanics lcsh:Electrical engineering. Electronics. Nuclear engineering lcsh:Engineering (General). Civil engineering (General) lcsh:TK1-9971 Titanium |
| Zdroj: | Materials Volume 14 Issue 5 Materials, Vol 14, Iss 1188, p 1188 (2021) |
| ISSN: | 1996-1944 |
| DOI: | 10.3390/ma14051188 |
| Popis: | By anodization and thermal oxidation at 600 °C, an oxide layer on Ti with excellent corrosion resistance in strong acid solutions was prepared. The structural properties of TiO2 films before and after thermal oxidation were investigated with methods of Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XRD) and X-ray diffraction (XPS). The electrochemical characterization was recorded via electrochemical impedance spectroscopy, potentiodynamic polarization and Mott–Schottky methods. XRD results show that a duplex rutile/anatase structure formed after oxidation, and the amount of anatase phase increased as the treatment time was prolonged from 3 to 9 h. XPS analysis indicates that as the thermal oxidation time increased, more Ti vacancies were present in the titanium oxide films, with decreased donor concentration. Longer thermal oxidation promoted the formation of hydroxides of titanium on the surface, which is helpful to improve the passive ability of the film. The anodized and thermally oxidized Ti samples showed relatively high corrosion resistance in 4 M HCl and 4 M H2SO4 solutions at 100 ± 5 °C. The passive current density values of the thermally oxidized samples were five orders of magnitude under the testing condition compared with that of the anodized sample. With the oxidation time prolonged, the passive current density decreased further to some extent. |
| Databáze: | OpenAIRE |
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