SiO2@Au@TiO2 core-shell nanostructures with tunable decoration amount of Au nanoparticles have been successfully synthesized by combining three individual synthesis steps with calcination. The as-prepared samples were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), N-2 adsorption-desorption, X-ray photoelectron emission spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy. The photocatalytic activities of the samples were evaluated by photocatalytic degradation of naproxen in aqueous solution under visible light irradiation. Results show that the as-obtained core-shell nanostructure is composed of a SiO2 core with an average diameter of similar to 337 nm, tunable content of Au nanoparticles adsorbed on the surface of SiO2 core, and an outer layer of TiO2 with an average thickness of similar to 7.0 nm. Photocatalysis experiments indicate that the SiO2@Au@TiO2 core-shell nanostructures with Au decoration amount of 0.1 wt% (denotes as SiAuTi-2) exhibit the highest photocatalytic activity since it has the suitable decoration amount of Au nanoparticles for harvesting the visible-light energy and for prohibiting the recombination of free excitons. For fast separation of the catalysts, superparamagnetic cores of Fe3O4 were embedded in the SiO2@Au@TiO2 core-shell nanostructures and hence they can be separated from aqueous solution by an external magnetic field within 10 min. (C) 2013 Elsevier B.V. All rights reserved.