Synthesis of TiO2-polycrystalline microspheres and its microstructure at various high temperatures

Synthesis of TiO2-polycrystalline microspheres and its microstructure at various high temperatures

TiO2-polycristalline microspheres were prepared by wet chemical synthesis using titanium aquo oxo chloride([Ti8O12(H2O)24]Cl8.HCl.7H2O) as titanium source. The morphology and structure of sample was observed using highresolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), FT-Ramanspectroscopy, FT-IR spectroscopy, X-ray diffraction (XRD) and high temperature X-ray diffraction (HT-XRD). Microstructureof TiO2 phases were determined from HT-XRD measurement data at various temperatures from 100 oC to 1000 oC at intervalsof 50 oC. The morphology of sample shows a distribution of microspheres of approximately 0.5 to 1.0 mm. Detailedmeasurements of sample from XRD spectra exhibit monoclinic structure (TiO2(B) phase) of TiO2-polycristalline microspheres. The HT-XRD results indicated that diffraction peaks of TiO2-polycrystalline microspheres are indexed as TiO2(B) phase from100 to 250 oC and as anatase phase from 300 to 650 oC, while mixed crystals of anatase and rutile were observed attemperatures measurement from 700 to 800oC. Finally, pure rutile phase has formed at temperatures measurement from 850to 1000 oC. The results of microstructure analysis show that the anatase structure could be indexed to I41/amd (no. 141) spacegroup with tetragonal symmetry at temperatures measurement: 600 and 750 oC, while the rutile structure could be indexedto P42/mnm (no. 136) space group with tetragonal symmetry at 750 and 950 oC.

TiO2-polycristalline microspheres were prepared by wet chemical synthesis using titanium aquo oxo chloride([Ti8O12(H2O)24]Cl8.HCl.7H2O) as titanium source. The morphology and structure of sample was observed using highresolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), FT-Ramanspectroscopy, FT-IR spectroscopy, X-ray diffraction (XRD) and high temperature X-ray diffraction (HT-XRD). Microstructureof TiO2 phases were determined from HT-XRD measurement data at various temperatures from 100 oC to 1000 oC at intervalsof 50 oC. The morphology of sample shows a distribution of microspheres of approximately 0.5 to 1.0 mm. Detailedmeasurements of sample from XRD spectra exhibit monoclinic structure (TiO2(B) phase) of TiO2-polycristalline microspheres. The HT-XRD results indicated that diffraction peaks of TiO2-polycrystalline microspheres are indexed as TiO2(B) phase from100 to 250 oC and as anatase phase from 300 to 650 oC, while mixed crystals of anatase and rutile were observed attemperatures measurement from 700 to 800oC. Finally, pure rutile phase has formed at temperatures measurement from 850to 1000 oC. The results of microstructure analysis show that the anatase structure could be indexed to I41/amd (no. 141) spacegroup with tetragonal symmetry at temperatures measurement: 600 and 750 oC, while the rutile structure could be indexedto P42/mnm (no. 136) space group with tetragonal symmetry at 750 and 950 oC.