Synthesis of alumina–titania solid solution by sol–gel method Original Research Article

Aluminum–titanium mixed metal oxides with various compositions were synthesized by sol–gel method and the photocatalytic activities for acetaldehyde decomposition were investigated. A mixture of aluminum isopropoxide and titanium butoxide in isopropanol was used as a precursor, and composition was controlled by varying relative concentration of each precursor in a mixture. X-ray diffraction analysis and Raman spectroscopy were employed to examine crystalline structure and surface area of synthesized samples was determined by BET method. Although structure transformation from anatase to rutile phase was observed for all synthesized samples, the transformation temperature was found to depend on sample composition (Al/Ti ratio). Photocatalytic decomposition of acetaldehyde was carried out in a closed borosilicate reactor under visible light illumination. The photocatalytic activity was measured with respect to composition and it was found to be strongly dependent on sample composition. Aluminum–titanium mixed oxides showed higher photocatalytic activity for acetaldehyde decomposition than either pure titania or pure alumina.