| Title | Hydrothermal rutile to anatase reverse phase transformation |
| Publication Type | Journal Article |
| Year of Publication | 2014 |
| Authors | McNicoll, C., Kemmitt T., and Golovko V. |
| Journal | International Journal of Nanotechnology |
| Volume | 11 |
| Issue | 5-8 |
| Pagination | 493 - 501 |
| Date Published | 2014 |
| ISSN | 14757435 (ISSN) |
| Keywords | Hydrothermal, Nanotechnology, Organic acids, oxalic acid, Oxide minerals, Phase transitions, Reverse phase, Rutile, Sols, TiO, titanium dioxide, Transformation |
| Abstract | TiO2 sols peptised with oxalic acid were synthesised with oxalic acid ratios from 0.25 to 1.0 oxalic acid per titanium. The resulting transparent colloidal sols of TiO2 contained a mixture of phases and sizes of TiO2 particles depending on the oxalic acid content. The sols were hydrothermally treated at different temperatures ranging from 85?phi;C to 275?phi;C. Treatment below 100?phi;C produced mostly anatase, while the decomposition of the oxalic acid between 120?phi;C and 170?phi;C allowed a phase change to rutile, with a rapid crystallite size increase from around 10 nm to 40 nm. AT-FTIR confirmed the complete decomposition of organic acids within the sols treated at 220?phi;C. Very limited rutile crystallite growth was observed above this temperature. However, sols produced with the lower oxalic acid content remained as rutile while those produced using higher initial oxalic: Ti ratios (0.5 and 1.0 M equivalents) induced a reverse phase transformation back to anatase phase TiO2. High resolution SEM showed that the anatase phase TiO2 crystallites grew to around 30 nm at the highest temperature used (275?phi;C) having indistinct morphology, while the rutile phase TiO2 were elongated rods growing up to 100 nm. Copyright © 2014 Inderscience Enterprises Ltd. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-84900443398&partnerID=40&md5=218913da3a053bf70db2f5a548e55957 |
| DOI | 10.1504/IJNT.2014.060570 |
