中文摘要：

以L-半胱氨酸为表面改性剂与粒径调节剂,采用水热法制备具有良好分散稳定性的磁性Fe3 O4纳米粒子.通过透射电镜（TEM）、扫描电镜（SEM）、X射线衍射仪（XRD）、比磁饱和强度测定仪（VSM）等对产物进行表征,研究L-半胱氨酸对磁性Fe3O4纳米粒子的形貌、粒径分布、晶型结构、分散稳定性等的影响,理论推导了L-半胱氨酸改性后的Fe3O4纳米粒子（L-Fe3O4纳米粒子）的生成机制,将该材料作为载体吸附金种后探讨其在催化对硝基苯酚方面的应用.结果表明：沉降22 h时,调节pH值为7.0制备的Fe3O4纳米粒子的沉降高度大约是L-Fe3O4纳米粒子的6.5倍;吸附金种后的L-Fe3O4纳米粒子催化效率大约是未改性Fe3O4纳米粒子的5倍.L-半胱氨酸有效的改善了Fe3O4纳米粒子与分散介质之间的相容性,保护并改善了纳米粒子的分散稳定性,在污水处理等方面有潜在的应用.

英文摘要：

Good dispersion stability magnetic Fe3O4 nanoparticles with L-cysteine （L-Fe3O4 NPs） for surface modification and particle size regulator were prepared by hydrothermal method.The Fe3O4 NPs were characterized by transmission electron microscopy （TEM）,scanning electron microscopy （SEM）,X-ray diffraction （XRD） and vibrating sample magnetometer （VSM）,respectively.The influence of L-cysteine on the morphology,particle diameter distribution,crystal structure and dispersion stability of Fe3 O4 NPs was studied.The results showed that sedimentation height of Fe3O4 NPs which adjusted to pH 7.0 was about 6.5 times than L-Fe3O4 NPs which sedimentation time was 22 h.Furthermore,4-nitrophenol catalyzed experiments were carried out for potential application in catalyzed field and we found that catalytic efficiency was increased significantly when Au absorbed by L-Fe3O4 NPs.Our results indicated that L-Fe3O4 NPs had excellent dispersion stability and had promising potential applications in waste water treatment field.