Enhancing the photocatalytic activity of nickel ferrite doped with graphene

Abstract

Graphene-nickel ferrite (G-NiFe2O4) has been successfully synthesized using graphene, NiSO4•6H2O and FeCl3•6H 2O as the raw materials by the hydrothermal method at 180 °C for 10 h. The as-synthesized sample was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometer at room temperature. The photo-Fenton degradations of methylene blue, rhodamine B and malachite green were conducted in the presence of oxalic acid using G-NiFe2O 4 as the photo-Fenton catalyst under visible light irradiation. The results showed that the G-NiFe2O4 catalyst can effectively decompose the organic pollutants under visible light irradiation and the decolorization ratio of methylene blue in the concentration of 20 mg/L reached over 87.8 % in 10 h, whereas the decolorization ratio was only 28.8 % when the NiFe2O4 was utilized as the catalyst under the similar conditions. The decolorization ratio maintained over 70 % after 8 runs via a magnetic field for separation, showing the G-NiFe2O4 catalyst is stable and easily separable for utilization.