Abstract
A systematic anal. of the influence of prepn. conditions in the alkali hydrothermal synthesis on the morphol. of TiO2 nanotubes is performed using HRTEM and low temp. nitrogen adsorption. The possible mechanisms of nanotube formation are reviewed and a mechanism based on the key stage of wrapping of intermediate multilayered titanate nanosheets is suggested. The driving force for wrapping is considered to be the mech. stress arising during crystn./dissoln. The av. diam. of the nanotubes was found to depend on the temp. and on the ratio of wt. of TiO2 to the vol. of sodium hydroxide soln. An increase in the temp. from 120 to 150 DegC results in an increase in the av. nanotube diam. Subsequent increases in the temp. result in the formation of non-hollow TiO2 nanofibers with an av. diam. of 75 nm, a wide distribution in diam. and a length in excess of 10 micro m. The increase of the TiO2:NaOH molar ratio results in an increase in the av. diam. of nanotubes and a decrease of surface area. The av. inner diam. of TiO2 nanotubes varied between 2 and 10 nm. The pore-size distribution was evaluated from TEM, and low-temp. nitrogen adsorption data using the BJH method. It was shown that nitrogen adsorption is a suitable method for characterization of the pore morphol. of nanotubes. [on SciFinder (R)]
Original language | English |
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Pages (from-to) | 3370-3377 |
Number of pages | 8 |
Journal | Journal of Materials Chemistry |
Volume | 14 |
Issue number | 22 |
Publication status | Published - 2004 |
Keywords
- Particle size
- titania nanotubes
- Pore size
- Nanotubes (titania
- Porous materials (mesoporous
- effects of hydrothermal synthesis conditions on mesoporous structure of TiO2 nanotubes)
- Surface area (effects of hydrothermal synthesis conditions on mesoporous structure of TiO2 nanotubes)
- titania nanotube hydrothermal synthesis structure