Porous TiO2-Al2O3 Composite Photocatalyst Prepared by Sol-gel Method: the Role of Calcination Temperature

Porous TiO2-Al2O3 composites were prepared by sol-gel method using tetrabutyl titanate and aluminum isopropoxide as the sol precursors. PEG1000 was used as the pore forming template. The materials were composed of anatase TiO2 and amorphous Al2O3. Long grooves distributed on the rough surfaces of the materials. FT-IR and XPS spectra indicated that the samples were composed of TiO2 and Al2O3. The porous TiO2-Al2O3 composite calcinated at 500 °C had average pore diameter of 14.56 nm, total pore volume of 0.3945 cm3·g-1, and specific surface area of 128.4 m2·g-1. Meanwhile, it had the maximum adsorption capacity and photocatalytic degradation activity. The maximum adsorption rate was 18.6% when methyl orange adsorption on the material reached the adsorption equilibrium in 30 min. After 90 min of irradiation, methyl orange photocatalytic degradation rate was 77.0%, while the total decoloration rate was 95.6% that was complicated by both photocatalytic degradation and adsorption.