Room temperature synthesis of titania microspheres by hydrolysis of titanium alkoxide using water vapor

In this study titania microspheres with diameters of 3–6 μm were synthesized at room temperature through hydrolysis of titanium alkoxide using water vapor. The discrete microsphere morphologies of the sample remained perfect after annealing at 100 °C for 36 h and the surface of the microspheres became smoother than as-prepared. As the annealing temperature increased, the diameter of the microspheres decreased while the crystallite size increased. Even after annealing at 700 °C, some of microspheres retained their morphologies perfectly but with much smaller diameter than before. The powders started to convert from amorphous to an anatase phase when annealing at temperatures higher than 200 °C for 2 h. When the annealing temperature increased up to 800 °C, the anatase phase converted to the rutile phase completely.