L-半胱氨酸改性Fe3O4纳米粒子的水热合成及其应用

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Fe₃O₄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。

Hydrothermal Synthesis and Application of the Fe_3O_4 Nanoparticles Modified with L-cysteine

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 Fe₃O₄ 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.