Polyvinyl Pyrrolidone-Assisted Solvothermal Synthesis of Fe3O4 Vesicular Nanospheres

Monodispersed Fe3O4 vesicular nanospheres with a diameter of 160 nm have been fabricated solvothermally in the mixed solution of ethylene glycol (EG) and ethylenediamine (en) with the surfactant polyvinyl pyrrolidone (PVP). The microstructure and magnetic properties of the products were characterized by XRD, Raman, SEM, TEM, HRTEM, N2 adsorption-desorption and SQUID techniques. The HRTEM result shows that spherical Fe3O4 nanoparticles are structurally uniform with a distinct lattice spacing of 2.6 Å, which can be assigned to the (311) crystal facet of cubic Fe3O4. Besides, the as-obtained Fe3O4 vesicular nanospheres are ferromagnetic with a saturation magnetization of 86.9 emu/g as high as its bulk counterpart, demonstrating its promising applications in advanced magnetic materials and biomedicine.