Preparation of ultrafine powders of TiO2 by hydrothermal H2O2 oxidation starting from metallic Ti

Abstract

Ultrafine powders of TiO₂ have been prepared by combined hydrothermal H₂O₂ oxidation. H₂O₂ oxidation and gel formation were performed at room temperature. Hydrothermal treatment was carried out at 140 °C. Anatase powder was formed in distilled water and rutile powder was formed in 1.0 mol dm^–3 nitric acid solution. DTA and XRD data showed that the anatase product transformed into rutile at 950–1000 °C in air. TEM showed that the average sizes of the acicular particles were ca.. 10 nm × 3 nm for anatase and ca. 30 nm × 5 nm for rutile.