Transformation from Anatase to Rutile Titania Using Hydrothermal Method: Investigation of Morphology and Thermal Stability

摘要

In this study, mixed A-R TiO_2 nanocrystals were successfully synthesized using the hydrothermal method. The effects of the annealing temperature on the structure, morphology and thermal stability of the mixed nanocrystal were investigated by XRD, Raman spectroscopy, TEM, FTIR, and TGA. XRD confirmed the presence of both the anatase and rutile phases synthesized at RT. All the major vibrational modes identified by Raman spectroscopy were in agreement with the results of XRD analysis. The spherical nanoparticles with average particle sizes between 19.799 and 38.685 nm were observed by TEM. SAED confirmed the presence of well-defined TiO_2 nanocrystals. FTIR confirmed the presence of the functional groups and the structural change that TiO_2 undergoes as the nanocrystals are subjected to postannealing. From the results of TGA analysis, we verified the existence of four mass losses of the TiO_2 nanocrystals at 31-114, 114-413, 413-600, and 600-700 ℃.