Synthesis and characterisation of novel titania impregnated kaolinite nano-photocatalyst

Nano-sized titanium dioxide (TiO2) has received a great attention in the field of research and development as a promising photocatalyst to promote the degradation of organic contaminants in water. One of the key technical challenges involved in separation and recovery of the photocatalyst particles from the water treatment system makes this technology unviable as an industrial process. A novel titania impregnated kaolinite (TiO2/K) photocatalyst was synthesized by a modified two step sol-gel method: hydrolysis of titanium(IV) butoxide and heterocoagulation with pre-treated kaolinite (K) clay. The TiO2/K photocatalysts were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET specific surface area measurements (BET). The photocatalytic activity was evaluated by the degradation of Congo red in aqueous solution. The TiO2/K photocatalyst had a rigid porous layer structure and promising nano-size properties, and demonstrated an enhanced adsorption and photocatalytic ability for the removal of Congo red. The TiO2/K photocatalyst can be easily separated and recovered from the water treatment system. The TiO2/K photocatalyst is expected to deliver a true engineering solution for an industrial water/wastewater treatment process. (C) 2008 Published by Elsevier Inc.