Generalized and Facile Synthesis of Fe<sub>3</sub>O<sub>4</sub>/MS (M = Zn, Cd, Hg, Pb, Co, and Ni) Nanocomposites

This study presents a novel method for the preparation of Fe<sub>3</sub>O<sub>4</sub>/MS (M = Zn, Cd, Hg, Pb, Co, and Ni) nanocomposites via a sonochemical aqueous route. This method is mild, convenient, cheap, and efficient. A creditable synthetic mechanism for the formation of the nanocomposites has been proposed. It can be found that the concentration of TAA plays an important role in the controlling of the size and density of the nanoparticles immobilized on the surface of the magnetic microspheres. Fe<sub>3</sub>O<sub>4</sub>/ZnS and Fe<sub>3</sub>O<sub>4</sub>/CdS nanocomposites display fluorescence and exhibit ferromagnetic behavior at room temperature. Photocatalytic activity studies demonstrate that the former ones have highly photocatalytic activity toward the photodegradation of eosin Y in aqueous solution. The catalytic efficiency only decreased by 5% when cyclic time was up to 15 cycles, which means that as-prepared Fe<sub>3</sub>O<sub>4</sub>/ZnS nanocomposites have promising applications not only in biomedical fields but also in organic synthesis or wastewater treatment as recyclable photocatalysts. Furthermore, this method can be extended to the synthesis of other magnetic nanocomposites.