Magnetic photocatalysts based on ferrite@ZrO2@TiO2 core-shell systems for degradation of aqueous pollutants

The versatility of core@shell systems comes from the combination of multiple properties, considering the specificity of each materials. In the present work, photocatalysts easily separated from the aqueous media were obtained, by the use of core@shell systems, CoMnFe 2 O 4 @ZrO 2 @TiO 2 , with different proportions of ZrO 2 and TiO 2 . The materials were synthesized by the modified Pechini method and characterized in relation to its structural, physical and morphological properties. The photocatalytic efficiency was evaluated using a cationic as target. All photocatalysts were easily separated from the aqueous solution using a magnet, despite the small amount of ferrite (10%, in wt) in the core@shell systems. A high efficiency (96%) was obtained in the decolorization of methylene blue using the system CoMnFe 2 O 4 @ZrO 2 @TiO 2 , with 85% of TiO 2 and 5% of ZrO 2 , after 16 h of UVC irradiation with 3 low power lamps (9 W). This decolorization is much higher than results obtained without ZrO 2 as intermediate phase in CoMnFe 2 O 4 @TiO 2 photocatalyst (49%) and without TiO 2 as active phase in CoMnFe 2 O 4 @ZrO 2 (40%), for the same irradiation time. • Magnetic core@shell photocatalysts were synthesized by the Pechini method. • An intermediate shell avoided diffusion of core cations into the photocatalytic shell. • High photocatalytic activity was attained with easily removable magnetic materials.