Sol-gel Preparation of TiO2-Al2O3 Composite Materials to Promote Photocatalytic Activity

A mixed precursor containing tetrabutyl titanate and aluminum isopropoxide was used to prepare TiO2-Al2O3 composite photocatalyst through sol-gel method. The influences of n(Ti)/n(Al) on material structure and photocatalytic activity were studied. The results revealed that the materials have crystal structure of anatase TiO2, and the variation of n(Ti)/n(Al) ratio has very little effect on TiO2 crystallite size and surface morphology. The materials are composed of anatase TiO2 and amorphous Al2O3, and have large surface area at high Al2O3 content. The TiO2-Al2O3 at n(Ti)/n(Al) of 12 has average pore size of 22.4 nm, total pore volume of 0.4493 cm3·g-1, and the highest photocatalytic activity. Methyl orange decoloration on the sample is as high as 95.2% after 90 min of irradiation.