Comparison of the phase transformation rate for TiO2 thin film and TiO2 nanorods

초록

Relative phase transformation rates are compared with TiO2 sol-gel thin film and TiO2 nanorods. TiO2 thin film was prepared with sol-gel process using titaanium isoproxide (TIP) as a precusor, ethanol as a solvent and HCl as a catalyst. The TiO2 nanorods were synthesized with low temperature proccess (100°C) using TIP, oleic acid, and aqueous trimethylamine. The prepared thin film and nanorods were annealed at 850°C for 3 h. X-ray diffraction patterns reveal that the TiO2 thin film and TiO2 nanorods have amorphase phase and anatase phase, respectively before annealing process. Approximately 60 and 3 % of TiO 2 thin film and TiO2 nanorods transformed from anatase phase to rutile phase after annealing at 850°C for 3 h. Relatively small amount of TiO2 nanorods transformed to rutile phase compared with TiO2 thin film. This small amount of phase transformation may be due to the small diameter of the TiO2 nanorods, which have thermodynamecally favorable anatase phase. © 2010 Copyright SPIE - The International Society for Optical Engineering.