Construction of magnetic BiOBr@Fe3O4 hybrid nanoparticles via a sol-gel route for photocatalysis application

Abstract

Development of a highly active visible-light-driven and magnetically recyclable photocatalyst is a challenge for chemical use of solar energy. In this study, Fe3O4 nanoparticles (NP), BiOBr and a superior magnetic separable BiOBr@Fe3O4 hybrid material have been synthesized via a facile chemical method. The structures, morphological, optical and physical properties of as-synthesized samples have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transforminfrared (FT-IR) spectroscopy, photoluminescence (PL) spectroscopy. The photocatalytic activity of the as-synthesized materials is evaluated by photocatalytic degradation of aromatic, heterocyclic organic compound such as methylene blue (MB) and 85% of MB could be removed by BiOBr@Fe3O4 hybrid within 60 min. It is found that the composite yield a significantly larger amount of hydroxyl radicals through free radical scavenging test. It is proposed that the observed synergistic effect between Fe3O4 and BiOBr is due to the charge transfer between the two oxides, improving the separation of the photogenerated charge carriers via the Z-scheme mechanism, and thus accelerating the photocatalytic degradation of MB and leading to high photocatalytic stability of BiOBr@Fe3O4 material.