Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Preparation and characterization of spindle-like Fe3O4 mesoporous nanoparticles | Zhang et al. Nanoscale Research Letters 2011 6 89 http content 6 1 89 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Preparation and characterization of spindle-like Fe3O4 mesoporous nanoparticles Shaofeng Zhang1 2 Wei Wu1 2 Xiangheng Xiao1 2 Juan Zhou1 2 Feng Ren1 2 Changzhong Jiang1 2 Abstract 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 a-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 a-Fe2O3 phase transformed into Fe3O4 phase after annealing in hydrogen atmosphere at 350 C. The as-prepared spindle-like Fe3O4 mesoporous NPs possess high Brunauer-Emmett-Teller BET surface area up to ca. m2 g-1. In addition the Fe3O4 NPs present higher saturation magnetization emu g-1 and excellent magnetic response behaviors which have great potential applications in magnetic separation technology. Introduction In the past few decades porous materials have been used in many fields such as filters catalysts cells supports optical materials and so on 1-3 . In general porous materials can be classified into three types depending on their pore diameters namely micropor-ous 2 nm meso- or transitional porous 2-50 nm and macroporous 50 nm materials respectively 4 . Currently the mesoporous materials have attracted growing research interests and have great impact in the applications of catalysis separation adsorption and sensing due to their special structural features such as special surface area and interior void 2 5-8 . On the other hand iron oxide nanomaterials have been extensively
