中文摘要：

以七水硫酸亚铁（Fe SO4·7H2O）与六水三氯化铁（Fe Cl3·6H2O）为原料,离子液体1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim]BF4）为添加剂,70℃下反应2 h制备了Fe3O4纳米粒子。通过X射线衍射仪（XRD）、傅里叶红外光谱（FT-IR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及热重分析（TG）等方法对样品的结构和形貌进行表征,并测试了所合成样品的磁性能。实验结果表明：离子液体辅助制备的Fe3O4纳米粒子形貌较为均一,呈近似球状,平均直径约为14 nm,产品在室温下表现出超顺磁性,饱和磁化强度为60.66 emu/g。利用密度泛函理论（DFT）计算模拟了Fe3O4分别与离子液体和水相互作用的电子结构,发现离子液体通过阴离子的桥联,更易吸附在Fe3O4晶粒表面。

英文摘要：

Fe3O4nanoparticles were synthesized from Fe SO4·7H2O and Fe Cl3·6H2O using ionic liquid1-butyl-3-methyl imidazolium tetrafluoroborate（ [Bmim]BF4） as additive at 70 ℃ for 2 h. The structure,morphology and magnetic properties of as-synthesized Fe3O4 nanoparticles were characterized by X-ray diffraction（ XRD）, fourier transform infrared spectroscopy（ FT-IR）, scanning electron microscopy（ SEM）,transmission electron microscopy（ TEM） and thermogravimetric（ TG） respectively.The morphology of Fe3O4 nanoparticles synthesized using the ionic liquid as additive is homogeneous and nearly spherical and the average particle size of the synthesized nanoparticles is about 14 nm. The product exhibits superparamagnetism with saturation magnetization of 60. 66 emu / g at room temperature.The interactional electronic structures between Fe3O4 and ionic liquid or H2 O were simulated respectively by density functional theory（ DFT）. It is found that ionic liquid is easier adsorbed to the face of Fe3O4 grain through the fiber-bridged of anion.