Microwave Treated Bentonite Clay Based TiO2 Composites: An Efficient Photocatalyst for Rapid Degradation of Methylene Blue.

The composites of TiO₂ and bentonite were synthesized under microwave conditions. Formation of anatase TiO₂ nanoparticles was achieved within 10 minutes by microwave treatment at 180 °C on the clay surface. Phase composition, particle morphology, specific surface area, chemical bonding etc. of these samples were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen gas adsorption method (BET) and fourier transform infrared spectroscopy (FTIR). The photo catalytic activity of the as prepared material to degrade methylene blue resulting in complete photomineralization to CO₂ and H₂O was monitored by UV-Vis spectroscopy and gas chromatography. The effect of TiO2 content on the photocatalytic activity was also investigated. Bentonite containing 50% TiO₂ by weight showed the highest photocatalytic activity because of its relatively large specific surface area and pore volume. Overall our findings show that the photocatalytic activity of resulting composite is more efficient than commercial nano-TiO₂ and thus could therefore be an economic competitive candidate for contaminated water remediation.