Synthesis of TiO2-coated CoFe2O4 photocatalysts applied to the photodegradation of atrazine and rhodamine B in water

Various strategies for the synthesis of anatase TiO2 nanoparticles and nanocomposites with particular morphologies and stability are currently generating a lot of interest and many research papers. In this study, composites of TiO2/COFe2O4 in nanometric sizes were prepared by the polymeric precursor method. These materials were characterized by X-ray diffraction, Raman spectroscopy, surface area through N-2 physisorption, Zeta potential, scanning and high-resolution transmission electron microscopy. The photocatalytic potential of the nanocomposites prepared was assessed by photodegradation of rhodamine B dye and atrazine pesticide under UV light. The materials showed photocatalytic activity due to the presence of TiO2 on their surface, associated with the magnetic activity of CoFe2O4 cores, which is useful for the separation and recovery of the photocatalysts after use in an oxidative process. In rhodamine photodegradation, pure TiO2 showed higher photocatalytic efficiency than the nanocomposites. However, in atrazine photodegradation, the nanocomposites were more effective, being this effect attributed to difference in charge at the surface of pure TiO2 and of nanocomposites, which enables adsorption processes of atrazine molecules on nanocomposites surface, and consequently, their higher photoactivity. (c) 2010 Elsevier B.V. All rights reserved.