一种Au@Fe_3O_4纳米复合粒子的快速合成方法

One Rapid Synthesis Approach of Au@Fe_3O_4 cComposite Nanoparticles

团簇状的Au@Fe_3O_4纳米复合粒子采用两步法进行合成。首先通过共沉淀法合成柠檬酸修饰的Fe_3O_4纳米粒子;其次以柠檬酸纳为温和的还原剂将HAuCl_4快速还原为Au纳米粒子而沉积在Fe_3O_4的表面。并考察了HAuCl_4及柠檬酸修饰的Fe_3O_4纳米粒子用量对合成过程的影响。采用紫外-可见分光光度计（UV-vis）、动态光散射仪（DLS）及透射扫描电镜（TEM）等测试手段对所制备的纳米粒子进行了表征。结果表明：当V（1%HAuCl_4）=1.8 m L,m（柠檬酸修饰的Fe_3O_4）=12.5 mg时,Au@Fe_3O_4纳米复合粒子的中心Au纳米粒子的粒径大小为20~50 nm左右而周围包覆的Fe_3O_4纳米粒子的大小为10 nm左右,且其在水中能够稳定的存在3个月而粒径大小无明显的变化。

The cluster Au@Fe_3O_4 nanoparticles were quickly synthesized by two-step method. Firstly citric acid modified Fe_3O_4 nanoparticles were prepared by co-precipitation and secondly we employed sodium citrate to reduce HAuCl_4 on the surface of Fe_3O_4 nanoparticles. Meanwhile, the dosage of HAuCl_4 and citric acid modified Fe_3O_4 nanoparticles on the synthesis process were also investigated. The obtained nanoparticles were characterized by UV-vis spectrometer, dynamic light scattering（DLS） and transmission electron microscopy（TEM）. The results demonstrated that when 1 % HAuCl_4 and citric acid modified Fe_3O_4 was added 1.8 m L and 12.5 mg, respectively, the obtained Au@Fe_3O_4 composite nanoparticles in water can be stable for three months while the corresponding hydrodynamic diameters have no evident differences. What＇s more, the central Au nanoparticles in size was about 20~50 nm, which surrounded by numerous Fe_3O_4 nanoparticles that the size was about 10 nm.