Fe nanoparticles@graphene composites (FGC) are successfully synthesized by using graphene oxide (GO) as a supporting matrix. GO is first treated with Fe3+ to form Fe3+@GO complexes. Then, by adding NaBH4 solution, Fe3+ and GO are simultaneously reduced in situ to Fe and graphene respectively, forming FGC hybrid composites. The structures, properties and applications of the hybrids thus obtained are investigated by X-ray diffraction, Raman spectroscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis and magnetization measurements. The hybrids are also evaluated for decolorization of methyl blue solution, a model dye in wastewater of dyeing industry. Compared with bare Fe particles, the high removal capacities of FGC are due to the increased adsorption sites in the hybrids, which are achieved by inhibiting the particle aggregation and reducing the size of Fe nanoparticles. (c) 2012 Elsevier B.V. All rights reserved.