Microwave-assisted synthesis and high dechlorination activity of magnetic FeNi broom-like nanostructures

A three-dimensional (3D) broom-like nanostructured magnetic FeNi catalyst was synthesized using inexpensive Fe and Ni as precursors in a controllable microwave-assisted route. In this 3D broom-like nanostructure, the length of an FeNi nanorod, which serves as a building block, depends on the molar content of Fe. With a decrease in the Fe content from 100 to 45% in the Fe(x)Ni(96-x) system, the length varies from 8 μm to 1 μm, which is corroborated by SEM, TEM, XRD, EDS and XPS. The magnetic behavior measurement results show that the magnetic saturation and coercivity are strongly influenced by the length of the nanorods and the Fe content. The sample of Fe nanorods gives a maximum magnetization saturation at 196 emu g(-1), and a maximum coercivity of 241.23 Oe is obtained for Fe78Ni22. These economical 3D FeNi broom-like nanostructures, with large surface areas and dispersed active sites, can dramatically facilitate the diffusion and transportation of a reactant to improve the reactivity. In particular, Fe89Ni11 broom-like nanostructures exert an excellent reactivity towards the reductive dechlorination of 1,1,2,2-tetrachloroethane.