Formation mechanism of anodic titanium oxide in mixed electrolytes
- Key Laboratory of Soft Chemistry and Functional Materials of Education Ministry, Nanjing University of Science and Technology, Nanjing 210094 (China)
- Microscopic Analysis Technology Center, Institute of Automation Chinese Academy of Sciences, Beijing 100190 (China)
Highlights: • Compact anodic titanium oxide (CATO) and anodic TiO{sub 2} nanotubes (ATNTs) were compared. • A distinct transform from CATO films into the porous ATNTs was observed firstly. • FESEM evidences for oxygen bubble mould effect were provided firstly. • Formation mechanisms for different titanium oxide films are confirmed consistent. - Abstract: The formation mechanism of anodic TiO{sub 2} nanotubes (ATNTs) remains mysterious and complicated. Usually, ATNTs are fabricated in pure NH{sub 4}F electrolytes rather than mixed electrolytes and Ti anodizations are carried out under potentiostatic rather than galvanostatic conditions. In this work, anodizations under the potentiostatic and galvanostatic conditions are conducted. The formation processes of titanium oxide film in different mixed electrolytes are explored in detail. By changing the mass ratios of oxalic acid and ammonium fluoride, different kinds of anodic titanium oxide films are fabricated: the compact anodic titanium oxide (CATO) films, transient-state anodic titanium oxide films and porous films (ATNTs). A distinct transform from CATO films into ATNTs was observed. Cavities within oxide and hemispheric bottoms are found, confirming the presence of oxygen bubble mould. Based on the electronic current and ionic current model, a consistent formation mechanism for three kinds of anodic titanium oxide films in mixed electrolytes is proposed.
- OSTI ID:
- 22730478
- Journal Information:
- Materials Research Bulletin, Vol. 95; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
Similar Records
Essential distinction between one-step anodization and two-step anodization of Ti
Novel Electrode Materials for Low-Temperature Solid-Oxide Fuel Cells