Facile preparation of Fe3O4@AgBr–ZnO nanocomposites as novel magnetically separable visible-light-driven photocatalysts

Novel magnetically separable Fe3O4@AgBr–ZnO nanocomposites with different weight ratios were successfully prepared by a facile refluxing method at a low temperature of 96 °C for 60 min. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDX), UV–vis diffuse reflectance spectra (DRS), Fourier transform-infrared (FT-IR), and vibrating sample magnetometer (VSM) techniques were employed to determine the structure, morphology, optical, and magnetic properties of the as-prepared samples. Photocatalytic examination of the nanocomposites was carried out using aqueous solution of rhodamine B (RhB) under visible light irradiation. The results demonstrate that weight ratio of Fe3O4 to AgBr–ZnO has remarkable influence on the photocatalytic activity. The nanocomposite with 1:6 weight ratio of Fe3O4 to AgBr–ZnO has superior activity in degradation of RhB. Furthermore, the photocatalyst can be easily separated from the reaction system simply by applying an external magnetic field. The degradation rate constant of the nanocomposite is about 8-fold greater than that of Fe3O4@ZnO nanocomposite. Finally, influence of refluxing time and calcination temperature on the degradation activity was investigated and the results were discussed.