Three-Layer Magnetic Nanocomposite Containing Semiconductor Nanoparticles as Catalyst for Dye Removal from Water Solutions under Visible Light

In the present work, a three-layer magnetic nanocomposite containing ceria nanoparticles was synthesized as Fe3O4@SiO2@CeO2 by precipitation method and after characterization was used as photocatalyst for the degradation of malachite green dye from industrial wastewater under visible light. The influence parameters such as pH, initial dye concentration, photocatalyst amount, and process time on the malachite green dye removal were investigated and optimized. Under optimum conditions (pH = 9, the photocatalyst amounts of 0.05 g, the reaction time of 40 min, and the initial solution concentration of 10 ppm), the results indicated that the synthesized nanostructure has a desirable performance for dye. The removal percentage remained higher than 90% after 5 times of use and the photocatalyst could be quickly separated from the aqueous solution with the assistance of the external magnetic field. According to the calculation, the second pseudo-model was selected as the kinetic model of photocatalytic degradation.