Rapid degradation of dyes in water by magnetic Fe0/Fe3O4/graphene composites

Magnetic Fe-0/Fe3O4/graphene has been successfully synthesized by a one-step reductionmethod and investigated in rapid degradation of dyes in thiswork. The materialwas characterized by N-2 sorption-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/Fe3O4/graphene had a layered structurewith Fe crystals highly dispersed in the interlayers of graphene, which could enhance themass transfer process between Fe-0/Fe3O4/graphene and pollutants. Fe-0/Fe3O4/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/Fe3O4/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/Fe3O4/graphene with dyesmainly included adsorption and enhanced reduction by the composite. Thus, Fe-0/Fe3O4/graphene prepared by the one-step reduction method has excellent performance in removal of dyes in water. (C) 2016 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.