Controlled Synthesis of Magnetite Porous/Hollow Nanoparticles Through a Template-Free Solvothermal Process.

Magnetite Fe3O4 porous/hollow nanospheres were synthesized controllably through a one-pot template-free solvothermal process, requiring only FeCl3 x 6H2O as iron precursor and addition of ammonium acetate in an ethylene glycol solution. SEM observations indicated that the porous/hollow nanospheres were composed of numerous small grains. The initial concentrations of Fe precursor and ammonium acetate as well as the molar ratio of Fe precursor to ammonium acetate played crucial roles to control particle diameter and porosity of the Fe3O4 porous/hollow nanospheres. The Fe3O4 porous/hollow nanospheres exhibited a ferromagnetic behavior with high magnetization saturation.