Kinetics of anatase transition to rutile TiO2 from titanium dioxide precursor powders synthesized by a sol-gel process

Kinetics of anatase transition to rutile TiO2 from titanium dioxide precursor powders synthesized by a sol-gel process have been studied using differential thermal analysis (DTA), X-ray diffraction, transmission electron microscopy (TEM), selected area electron diffraction (SAED), nano beam electron diffraction (NBED) and high resolution TEM (HRTEM). The DTA result shows residual organic matter decomposed at 436 K. The transition temperature for amorphous precursor powders converted to anatase TiO2 occurred at 739 K. Moreover, the full anatase transition to rutile TiO2 occurred at 1001 K. The activation energy of anatase TiO2 formation was 128.9 kJ/mol. On the other hand, the activation energy of anatase transition to rutile TiO2 was 328.4 kJ/mol. Mesoporous structures can be observed in the TEM image.