Hydrothermal preparation of nanosized brookite powders

Titania powders in pure brookite form were synthesized by hydrothermal treatment of titanium(IV) salt solutions. Two kinds of starting materials, titanium sulfate and titanium tetrachloride, were used in the hydrothermal reactions. The effects of preparation conditions on the polymorphous form and morphology of the titanium dioxide powders were studied. These conditions included precursor species, precursor pretreatment, pH, and reaction temperature. The conditions that lead to brookite formation versus other phases, such as anatase and rutile, are generalized. The morphologic differences of the three polymorphous powders are shown.