Facile fabrication of hierarchical porous ZnO/Fe3O4 composites with enhanced magnetic, photocatalytic and antibacterial properties

Hierarchical porous ZnO/Fe3O4 composites were fabricated through a facile surfactant-free method. The as-prepared samples were characterized using different instrumental techniques. The X-ray diffraction and energy dispersive X-ray results showed that the as-prepared samples were two-phase photocatalysts consisted of ZnO and Fe3O4. The UV-vis diffuse reflectance spectroscopy result indicated that the addition of Fe3O4 modified the optical properties of the photocatalysts. Under visible light irradiation, the ZnO/Fe3O4 exhibited enhanced photocatalytic performance for phenol degradation and Escherichia coli inactivation compared to ZnO. The photocatalytic enhancement of ZnO/Fe3O4 was attributed to the effective electron-hole pairs separation as verified by the photoluminescence spectra. The ZnO/Fe3O4 also exhibited magnetic properties, which can easily be recovered using an external magnet along with good reusability.