Photocatalytic activity of magnetically recoverable MnFe2O4/g-C3N4/TiO2 nanocomposite under simulated solar light irradiation

Abstract

A magnetic nanocomposite composed of manganese ferrite (MnFe2O4), graphitic-carbon nitride (g-C3N4) and titanium dioxide-P25 (TiO2) was synthesized via chemical impregnation method. The as-synthesized nanocomposite (MnFe2O4/g-C3N4/TiO2) was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution TEM (HR-TEM) elemental mapping, energy dispersive X-ray spectroscopy (EDX), UV–visible diffuse reflectance spectroscopy (UV-vis-DRS), photoluminescence (PL), B.E.T. surface area analysis, X-ray photo-electron spectroscopy and vibrating sample magnetometery (VSM) techniques. The band gap of TiO2 was decreased after surface modification with MnFe2O4/g-C3N4. The photocatalytic activity was tested for the degradation of methyl orange (MO) dye as a model pollutant under simulated solar light irradiation. It was found that MnFe2O4/g-C3N4/TiO2 displayed excellent photocatalytic activity than that of g-C3N4, MnFe2O4 and MnFe2O4/g-C3N4. The enhancement in the photocatalytic activity was ascribed to the synergism between TiO2, g-C3N4 and MnFe2O4. VSM results revealed that ferromagnetism was retained in the nanocomposite (MnFe2O4/g-C3N4/TiO2) and it could be easily removed using an external magnet after the photo-reaction. Besides, the durability and stability of magnetic nanocomposite was tested by recycling experiments.