Preparation and characterization of spindle-like Fe3O4 mesoporous nanoparticles

Magnetic spindle-like Fe3O4 mesoporous nanoparticles with a length of 200 nm and diameter of 60 nm were successfully synthesized by reducing the spindle-like alpha-Fe2O3 NPs which were prepared by forced hydrolysis method. The obtained samples were characterized by transmission electron microscopy, powder X-ray diffraction, attenuated total reflection fourier transform infrared spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and nitrogen adsorption-desorption analysis techniques. The results show that alpha-Fe2O3 phase transformed into Fe3O4 phase after annealing in hydrogen atmosphere at 350 degrees C. The as-prepared spindle-like Fe3O4 mesoporous NPs possess high Brunauer-Emmett-Teller (BET) surface area up to ca. 7.9 m(2) g(-1). In addition, the Fe3O4 NPs present higher saturation magnetization (85.2 emu g(-1)) and excellent magnetic response behaviors, which have great potential applications in magnetic separation technology.