Crystallization of amorphous hydrous titania under hydrothermal hot-pressing conditions

Amorphous hydrous titania prepared by hydrolysis of tetraethylorthotitanate was crystallized to anatase under hydrothermal hot-pressing conditions. Crystallization occurred even at 100 °C. The hydrothermal hot-pressing conditions changed crystallite size of anatase. Reaction pressure had no effect on the crystallite size. Increase in reaction temperature and reaction time up to 60 min, increased the crystallite size by growth of anatase nuclei by the dissolution and deposition mechanism. Increase in water content of hydrous titania decreased the crystallite size. The presence of water accelerated the nucleation of anatase.