In the present work, a facile hydrothermal route is employed for the synthesis of highly aligned arrays of Fe3O4 nanoplates on a 3D nickel foam substrate. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal the crucial role of the nickel foam substrate on the morphology of the produced Fe3O4. Synthesis on a nickel foam results in a nanoplate morphology while in absence of the substrate, highly agglomerated Fe3O4 nanoparticles are achieved. SEM studies show that, in the early stages of hydrothermal treatment, small Fe3O4 nuclei form on the surface of the Ni foam which grow into nanoplates by increasing the duration from 2 to 18 h. According to X-ray diffraction studies Fe3O4 nanoplates are single phase. Brunauer-Emmett-Teller (BET) measurements, show that Fe3O4 decorated Ni foams have a surface area 26 times higher than the as-received foam. Vibrating sample magnetometer (VSM) studies also show that Fe3O4 decorated Ni foams have a superparamagnetic behavior with a high magnetization saturation value of 69.97 emu g-1. Such high surface area and magnetism makes this 3D composite an excellent material for electromagnetic shielding applications.

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