Synthesize TiO2 microspheres self-assembled from nanorods via hydrothermal treatment

The TiO₂ microspheres were deposited on the glass substrates under certain conditions via hydrothermal reaction using 0.15 mol·L⁻¹ TiCl₃ saturated NaCl aqueous solution adding urea as an additive. The TiO₂ is characterized rutile by results of SEM, TEM and XRD techniques, the TiO₂ microspheres are large scale assembled from TiO₂ nanorods. The affections on the products by the factors of the contents of urea being an additive (the key techniques), the reaction temperature, the reaction time and the concentration of TiCl₃ were studied. The optimum condition was found, and the mechanism of reactions was discussed also. Supported by the State Key Project for Fundamental Research (G199064504) and the Special Research Foundation of the National Natural Science Foundation of China (Grant Nos. 90306011 and 20341003)