Rapid degradation of dyes in water by magnetic Fe~0/Fe3O4/graphene composites

Magnetic Fe~0/FeO/graphene has been successfully synthesized by a one-step reduction method and investigated in rapid degradation of dyes in this work. The material was characterized by Nsorption–desorption, scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR), vibrating-sample magnetometer(VSM) measurements and X-ray photoelectron spectroscopy(XPS). The results indicated that Fe~0/FeO/graphene had a layered structure with Fe crystals highly dispersed in the interlayers of graphene, which could enhance the mass transfer process between Fe~0/FeO/graphene and pollutants. Fe~0/FeO/graphene exhibited ferromagnetism and could be easily separated and re-dispersed for reuse in water. Typical dyes, such as Methyl Orange, Methylene Blue and Crystal Violet, could be decolorized by Fe~0/FeO/graphene rapidly. After 20 min, the decolorization efficiencies of methyl orange, methylene blue and crystal violet were 94.78%, 91.60% and 89.07%, respectively. The reaction mechanism of Fe~0/FeO/graphene with dyes mainly included adsorption and enhanced reduction by the composite. Thus, Fe~0/FeO/graphene prepared by the one-step reduction method has excellent performance in removal of dyes in water.