Photocatalytic Properties of Titanium Dioxide

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Wold This research focusses on the investigation of the photocatalytic activity of titanium and related compounds toward the degradation of organic contaminants present in aqueous solutions at low concentrations. Previous studies have shown that the activity of titanium oxide is dependent on the method of preparation, and that the best samples are obtained from a volatile precursor. Furthermore, the formation of active surface states can be enhanced by the addition of a small quantity (~3%) of a transition metal oxide containing a high formal valence state metal, e.a. tungsten oxides or molybdenum oxides. This increase in active site formation has been related to an increase in Lewis acidity as evidenced by increased reactivity with n-butylamine. The proposed research will, therefore, be directed as follows: 1) attempts will be made to prepare titanium with a higher photocatalytic activity than the best titanium oxide samples studied to date; 2) a second group of oxides will also be prepared by the use of supercritical carbon dioxide and they involve two oxides which do not form a ternary phase in bulk form; and 3)the work will be extended to a family of compounds closely related to rutile in which three titanium ions are replaced by two pentavalent and one divalent ions. %%% The photocatalytic oxidation of organic compounds in an aqueous solution containing a suspension of titanium(IV) oxide is a comparatively new method for the removal of impurities from water. The photoactivating light required is sunlight or near UV. Many organic compounds have been shown to be oxidized to carbon dioxide by this method. It has potential application in the treatment of both waste and drinking water. Titanium oxide thin film coating on floating beads has potential to photocatalyze the oxidation of organic compounds floating on water, such as those typically resulting from an oil spill. This research focusses on the investigation of the photocatalytic activity of Titaniu m and related compounds toward the degradation of organic contaminants present in aqueous solutions at low concentrations.