| Title | In situ observation of the stability of anatase nanoparticles and their transformation to rutile in an acidic solution. | | Author(s) | Jung HS, Shin H, Kim JR, Kim JY, Hong KS, Lee JK | | Institution | School of Materials Science & Engineering, Seoul National University, Seoul 151-742, Korea. | | Source | Langmuir 2004 Dec 21; 20(26):11732-7. | | Abstract | Thermodynamic stability of anatase nanoparticles and their transformation behaviors to rutile phase in an acidic solution was investigated in situ at two different peptization temperatures using a freeze-drying method. When peptized at 30 degrees C, the initial product was anatase with a significantly distorted atomic structure, a significant amount of hydroxyl group and Ti3+ ions, and, thus, a thermodynamically unstable state. The instability of 30 degrees C-peptized anatase was responsible for a suitable transformation to rutile later via dissolution of the anatase to form a titanium hydroxylate, followed by reprecipitation into rutile. On the other hand, 80 degrees C-peptized anatase had a relatively more ordered atomic structure, a much reduced amount of hydroxyl group, negligible Ti3+ ions, and, thus, a thermodynamically more stable state. Plausible reasons why the 80 degrees C-peptized anatase does not transform to rutile were deduced. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 15595805 |
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