Highly hydrophobic TiO2 pillared clay for photocatalytic degradation of organic compounds in water

Four kinds of TiO2 pillared clays were prepared from different raw clays (montmorillonite, saponite, fluorine hectorite and fluorine mica), and their surface hydrophobicities and performances in adsorption-photocatalytic degradation of plithalate esters (di-n-butyl phthalate and dimethyl phthalate) were investigated. It was found that surface hydrophobicity of TiO2 pillared clays largely varied with the host clay: it increased in the order saponite < fluorine hectorite < montmorillonite < fluorine mica. The order of performance in adsorption and successive photocatalytic degradation of phthalate ester was consistent with that of surface hydrophobicity. It was clarified that employing the host clay that enhances surface hydrophobicity of the TiO2 pillared clay, such as fluorine mica, is quite an efficient way to obtain highly active photocatalysts for photodegradation of organic compounds in water. (C) 2003 Elsevier Inc. All rights reserved.