Synthesis of Nanosized Anatase by Hydrolysis of Tetrabutoxytitanium at Various pH Values

Resumo

Hydrolysis of water-ethanol solutions of tetrabutoxytitanium (TBT) in the presence of a chelating agent at various pH values and 100°C yielded nanosized anatase or titanium oxyhydrate. When precipitation occurred at pH of 0.8–8.6, anatase was formed; its crystallite size after calcination at 400°C was 4.8–7.1 nm. Precipitation at pH 10.5–12.7 yielded a poorly crystallized oxyhydrate phase, which converted, after being calcined at 400°C, to a mixture of an oxide phase (unidentifiable by X-rays) and anatase having crystallite sizes of 41–42 nm. Scanning electron microscopy verified the crystallite size determined by X-ray powder diffraction. Benzene adsorption by the prepared oxide materials decayed rapidly from 10 to 0.5 g/100 g adsorbent as pH in the solutions used in the synthesis increased.