ROOM-TEMPERATURE SYNTHESIS OF CRYSTALLINE METAL-OXIDES

Crystalline titanium dioxide powders have been synthesized as either r utile or anatase from aqueous solutions at low temperatures (T less th an or equal to 100 degrees C) and atmospheric pressure. First, a sol i s prepared by the hydrolysis of a titanium alkoxide in an acidic solut ion. The sol is subsequently heated at different rates to produce the different crystalline phases of titanium dioxide. Powder characterizat ion was carried out using X-ray diffraction, scanning electron microsc opy and high resolution transmission electron microscopy. In general, the precipitate size was observed to be between 50 and 100 nm. Possibl e mechanisms involved in determining the crystal variants are discusse d.