Preparation of magnetically separable Fe3O4/BiOI nanocomposites and its visible photocatalytic activity

Novel magnetic Fe3O4/BiOI nanocomposites with visible light response were successfully fabricated through a facile and economical method at low temperature and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), respectively. The Fe3O4/BiOI nanocomposites were further employed in photodegrading rhodamine B (RhB). After 40 min, RhB removal rate reached to 90.1%, which was superior to the pure BiOI (50.3%). The enhanced photocatalytic performance of Fe3O4/BiOI nanocomposites may be attributed to the separation efficiency of the carriers. After five recycles for the photodegradation of RhB, the Fe3O4/BiOI nanocomposites did not exhibit any significant loss of activity, confirming the photocatalyst was essentially stable. Moreover, direct hole transfers and radical dotO2− are proved to be the dominant reactive species in the photodegradation of RhB over Fe3O4/BiOI nanocomposites.