Phosphotungstic acid anchored to amino-functionalized core-shell magnetic mesoporous silica microspheres: A magnetically recoverable nanocomposite with enhanced photocatalytic activity

H3PW12O40 was successfully anchored to the surface of amino-functionalized Fe3O4@SiO2@meso-SiO2 microspheres by means of chemical bonding to aminosilane groups, aiming to remove unwanted organic compounds from aqueous media. The resultant multifunctional microspheres were thoroughly characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, infrared spectroscopy, inductively coupled plasma, and N-2 adsorption-desorption. The as-prepared microspheres possess unique properties including high magnetization (46.8 emu g(-1)), large BET surface area (135 m(2) g(-1)), and highly open mesopores (similar to 5.0 nm), and H3PW12O40 loading is calculated to be similar to 16.8%; and as a result, the as-prepared microspheres exhibit enhanced performance in degrading dyes under UV irradiation compared with pure H3PW12O40. Additionally, the photocatalyst can be easily recycled using an external magnetic field without losing the photocatalytic activity. (C) 2012 Elsevier Inc. All rights reserved.