Preparation of organoclay having titania nano-crystals in interlayer hydrophobic field and its characterization

Abstract

To prepare the material for cleaning up the water polluted by the toxic organic compounds with poor polarity such the endocrine disruptor chemicals, we attempted to prepare the cation-exchangeable titania-pillared clay by the hydrothermal synthesis. White powder obtained by the hydrothermal treatment of the montmorillonite with titania precursor in water still had the cation-exchangeable property. Both TEM image and XRD patterns showed that anatase-type nano-crystals (crystalline size: ca. 20 nm) were incorporated in the montmorillonite interlayer space. The organoclay having titania nano-crystals (OCT) could be prepare by intercalating the cetyltrimentylammonium cations to the montmorillonite with titania nano-crystals (CT) due to the cation-exchange reaction. The adsorption amount of bisphenol A (BPA) by the OCT from water was about 6th times larger than that by the CT, because the OCT has higher hydrophobicity than CT. From UV irradiation experiment by 300 W high-pressure Hg lamp, it was found that OCT exhibited the higher photocatalytic decomposition ability for BPA dissolved in water than both CT and titania nano-crystal powder, which was synthesized under the hydrothermal condition. Moreover, the present OCT exhibited the high durability against the continuous UV irradiation.