Magnetically Separable and Reusable Fe3O4/ZnO/Nanographene Platelets Photocatalyst for the Removal of Dye

Abstract

In this study, we report the sol-gel synthesis of nanocomposite Fe3O4/ZnO with nanographene platelets (NGP)and characterized by suitable techniques, including field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), UV-visible diffuse reflectance spectroscopy and vibrating sample magnetometer. The as-synthesized Fe3O4/ZnO/NGP nanocomposites materials were used for photocatalyst under UV as well as visible light irradiation to remove methylene blue as a model of organic polutan. The XRD spectra reveal peaks that can be attributed to cubic spinel Fe3O4, hexagonal wurtzite ZnO and nanographene platelets structure. The FESEM images show Fe3O4/ZnO uniformly decorating NGP sheets. EDX analysis signifies the formation of Fe3O4/ZnO/NGP. The photocatalytic activity was found to be ZnO loading dependent. Higher ZnO loading lead to higher rate of photocatalytic activity under UV light irradiation, while the opposite trend observed under visible light irradiation. The addition of NGP effectively enhanced the photocatalytic performance of Fe3O4/ZnO nanocomposites. Separation of Fe3O4/ZnO/NGP nanocomposites from the solution could be achieved by applying an external magnetic field, demonstrating the magnetic properties of the nanocomposites.