CdS urchin-like microspheres/α-Fe₂O₃ and CdS/Fe₃O₄ nanoparticles heterostructures with improved photocatalytic recycled activities.

The heterostructures of three-dimensional CdS urchin-like microspheres separately decorated with hematite α-Fe2O3 or magnetite Fe3O4 nanoparticles were successfully synthesized via a two-step solvothermal deposition. Each CdS urchin-like microspheres had an average diameter of 2 μm, which was composed of nanorods with average diameters of 10nm. α-Fe2O3 and Fe3O4 nanoparticles, with diameters of about 20 nm and 30 nm, respectively, anchored on the nanorods of CdS urchins. The photoluminescence behaviors of CdS urchins were conserved in both CdS/α-Fe2O3 and CdS/Fe3O4 heteronanostructures, and CdS/Fe3O4 heteronanostructure displayed ferromagnetic properties of the Fe3O4 nanoparticles, which makes it easily magnetically separated from the dispersion after photocatalysis and hence reused. Furthermore, the CdS/α-Fe2O3 heteronanostructure exhibited superior photocatalytic performances under visible light irradiation over pure CdS urchins and both the heteronanostructures showed improved photocatalytic recycled activities.