Preparation and photocatalytic activity of silver and TiO2 nanoparticles/montmorillonite composites

Ag–TiO₂/montmorillonite (Ag–TiO₂/MMT) was synthesized as photocatalyst using TiCl₄ hydrolysis to introduce nanosized TiO₂ into the interlayer space of the montmorillonite (MMT). Stable pillared TiO₂/MMT was obtained by calcination at 500 °C, then silver was loaded by reduction of silver nitrate. The physico–chemical properties of the photocatalyst were determined by X-ray diffraction (XRD), infrared spectroscopy (IR), atomic absorption spectrophotometer (AAS), nitrogen gas adsorption (BET method) and UV–Visible spectra. The photooxidation activity for methylene blue (M.B.) degradation was as follows: Ag–TiO₂/MMT > TiO₂/MMT > TiO₂(P25). Among them Ag–TiO₂/MMT had the highest photooxidation activity because of its larger specific surface caused by pillaring and loading of silver for improving its light absorption.