Magnetically Separable Fe₃O₄/TiO₂ Hollow Spheres: Fabrication and Photocatalytic Activity

Abstract

Well-defined magnetic separable, hollow spherical Fe₃O₄/TiO₂ hybrid photocatalysts were successfully prepared through a poly(styrene−acrylic acid) (PSA) template method. This bifunctional product was characterized in terms of the particle size, surface morphology, chemical composition, and magnetic properties using transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction (XRD) patterns. The <i>M</i>−<i>H</i> hysteresis loop for Fe₃O₄/TiO₂ hollow spheres indicates that the composite spheres show superparamagnetic characteristics at room temperature. These magnetic TiO₂ composites with hollow nature exhibit good photocatalytic activity under UV light irradiation and can be recycled six times by magnetic separation without major loss of activity. This method can be further applied to synthesize other bifunctional hollow spheres, such as Fe₃O₄/SnO₂ and Fe₃O₄/CdS.