One-pot template synthesis of Ti-Al-containing mesoporous silicas and their application as potential photocatalytic degradation of chlorophenols

This article presents preparation, characterization and evaluation of heterogeneous Titanium based alumina mesoporous silica catalysts for the photo degradation of chlorophenols in aqueous solution. For more economic application, a series of silica, Al2O3-SiO2 and TiO2-Al2O3-SiO2 are prepared using linear alkylbenzene sulfonic acid as a novel structure directing agent. Two Ti-Al-SiO2 samples were prepared by direct synthesis using different titanium sources. The prepared samples are characterized by combination of various physicochemical techniques, such as XRD, N-2 physisorption, FT-IR, UV-vis, SEM and TEM. The prepared mesoporous materials are applied in the presence of UV irradiation for photodegradation of chlorophenols as pollutants in water. The results reveal that the photodegradation process of 4-chlorophenol (4-CP) is completed within 40 min, while reach 67.3% for 2-chlorophenol (2-CP) within 130 min. Moreover, the titanium precursor species and the catalyst dosage (0.1-0.4 g/l) affect the photocatalytic activity of prepared catalysts for 2-chlorophenol degradation. Finally, the concentration of acetate and chloride ions formed during the degradation process can also affect the activity of the prepared catalysts. (C) 2011 Elsevier B.V. All rights reserved.