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This paper presents a study on the development of silver doped titania materials on clay support and their application for phenol photooxidation. Silver was incorporated by direct calcination of the sol-gel titania with silver nitrate added in various amounts. The silver ion was reduced during calcination of the sol-gel material via decomposition of silver nitrate. The structural characters of materials were studied by X-ray diffraction (XRD), diffuse reflectance spectra (DRS). The photocatalytic activity of silver doped titania photocatalyst and that of this mixture on clay support for phenol degradation were examined. The addition of increasing amounts of silver, for batches of samples, significantly increases the rate of degradation of phenol. This is attributed to the increasing visible absorption capacity due to the presence of silver nanoparticles. The better separation between electrons and holes on the modified TiO2 surface allowed more efficiency for the oxidation reactions.

In this work the mixed Al-Fe pillared bentonite was developed and tested as a heterogeneous catalyst for the photo-Fenton oxidation of phenol under solar light irradiation. The structural characteristics of the catalyst were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Al-Fe pillared clay exhibits higher basal distance than original bentonite. The effect of pH to the degradation of phenol and the reusability of the catalyst were addressed.The results of photocatalytic experiments indicate that the heterogeneous photo-Fenton process employing the Al-Fe pillared clay as a photocatalyst possesses a high potential for phenol degradation. During the photocatalytic reaction, the amount of iron leaching out increases as a function of time. Significantly lower concentration of Fe 2+ and Fe 3+ in the solution after the treatment could give a great advantage to the mixed Al-Fe pillared bentonite/H2O2 system over the homogeneous Fenton system.