RESUMO
In the present study copper and iron oxides loaded TiO2 catalysts are prepared by the deposition-precipitation method (DP) and the photocatalytic efficiency of these catalysts are tested for the degradation of Rose Bengal dye (Acid Red 94) under sunlight. The catalysts are characterized by XRD, TEM and UV-vis diffuse reflectance spectral analysis. It is interesting to note that the rutile form of commercial TiO2 is competently converted into anatase after loading oxides of Cu, Fe and Cu-Fe on TiO2 as evident from XRD analysis. This result is consistence with the result obtained in UV-vis diffuse reflectance spectra. TEM analysis confirms the nano particles of Cu and Fe deposited on TiO2. Photocatalytic studies were performed in a batch reactor under solar radiation. Preliminary studies are performed to understand the photocatalytic degradability of the dye and optimization of catalyst weight and dye concentration. Kinetic studies were done at different dye concentrations and it was found that the rate equation followed first order kinetics and obeyed Langmuir-Hinshelwood model. The comparison of the activity of blank TiO2, copper or/and iron oxides loaded TiO2 catalysts showed that the Cu and Fe oxide loaded catalysts are more active than pure TiO2 and also the Cu-Fe oxides co-loaded TiO2 catalysts showed much best activity. The order of activity of the catalysts is in the following order: Cu-Fe/TiO2 > Fe/TiO2 > Cu/TiO2 > TiO2. The enhanced activity of metal oxide loaded TiO2 is attributed to the presence of TiO2 in anatase form after loading, which enhanced the charge transfer from the TiO2 to adsorbed molecules for reaction.
