Preparation and characterization of hydrophobic TiO2 pillared clay:: The effect of acid hydrolysis catalyst and doped Pt amount on photocatalytic activity

Titanium hydrate sols were prepared using different acid hydrolysis catalysts, i.e., acetic acid and hydrochloric acid. The platinum-doped TiO2 sol-gels were also synthesized by adding K2PtCl6 into the titanium hydrate sols. The hydrophobic montmorillonite clay, treated with organic cationic surfactant, i.e., hexadecyltrimethylammonium bromide, was used as a template to prepare TiO2 pillared photocatalyst with the above sols. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX) were employed to characterize the resulting photocatalysts. The adsorption performance and photoactivity of prepared pillared clays were studied by using methyl orange as a model organic pollutant. The preliminary results indicated that the hydrophobic TiO2 pillared clay prepared with acetic acid as the acid hydrolysis catalysts possessed higher photocatalytic activity than that with hydrochloric acid. Due to the excellent sedimentation property of the clay, the resulting pillared photocatalyst is easily recovered and reused in the postrun treatment. Also the doping of platinum into the hydrophobic photocatalyst can increase the photocatalytic activity significantly. (C) 2008 Elsevier Inc. All rights reserved.