The synthesis of nanosized TiO_(2) powder using a sol-gel method with TiCl_(4) as a precursor

摘要

Nanosized TiO_(2) powder with anatase structure was synthesized by a sol-gel method using TiCl_(4) ethanol solution as a precursor. The grain size of TiO_(2) powder was homogenous and was about 10 nm after the precursor was calcined at 500℃ for 1 hour. Anatase TiO_(2) powder formed after the precursor was calcined at a temperature ranging from 300℃ to 550℃. The gelatinizing mechanism of TiCl_(4) in ethanol solution can be described as followings. When mixed with ethanol, TiCl_(4) reacted with ethanol to form TiCl_(x)(OCH_(2)CH_(3))_(4-x) species and HCl gas. During gelatinizing process, TiCl_(x)(OCH_(2)CH_(3))_(4-x) species absorbed water from atmosphere to form Ti(OH)_(4) precursor, which was polymerized to be an inorganic polymer. The formation of inorganic polymer of Ti(OH)_(4) was intensified with gelatinizing time. In contrast, the organic component was removed from the precursor. The formation of anatase TiO_(2) can also be promoted by increasing gelatinizing time. The influence of alcohol on the reacting progress and dispersivity was also studied. The size and activity of alcohol molecule were found to have influence on the polymerization and mineralization degree of the precursor and the dispersivity of TiO_(2) powders.