Self-Assemblies of Acicular Hollow Fe/C Nanostructures

Self-assemblies of acicular hollow Fe/C structures were synthesized using D-glucose monohydrate and ferric chloride as precursors by a simple hydrothermal process followed by carbonization at 800 °C. The self-assembled structures with an overall diameter of 15~20 µm composed of radially formed hollow needles from a central core with an average diameter of ca. 1 µm and a length up to 10 µm. The end of the needles was revealed to be a awl shape with a hollow structure formed during the self-assembly process and the subsequent heat treatment. The hollow structure was probably caused by the Kirkendall effect at 800 °C. The materials exhibit ferromagnetic characteristic with saturation magnetization (Ms), remanent magnetization (Mr), and coercivity (Hc) of 22.2 emu/g, 3 emu/g, and 151.22 Oe, respectively, with Ms much lower than that of Fe3O4.