新型磁性荧光Fe3O4-CdSe纳米复合材料的制备

以1-十八烯作为高沸点溶剂, 在磁性粒子表面沉积量子点获得新型的磁性荧光Fe₃O₄-CdSe 纳米异质结构. 首先以乙酰丙酮铁(Fe(acac)₃)为前驱体, 二苯醚为溶剂, 油酸为表面活性剂和油胺(OAm)为表面活性剂兼还原剂, 通过溶剂热法制备单分散性的Fe₃O₄ 纳米粒子. 然后以1-十八烯为高沸点溶剂, CdO 为镉源,TOP-Se为硒源, 十六胺为表面活性剂以及硬脂酸为生长促进剂和成核剂制备得到新型的Fe₃O₄-CdSe纳米异质结构. 通过透射电镜(TEM), 傅里叶变换红外(FTIR)光谱, X射线衍射(XRD)谱, X射线光电子能谱(XPS)分析仪, 振动样品磁强计(VSM), 紫外-可见(UV-Vis)光谱和光致发光(PL)等手段对Fe₃O₄-CdSe 纳米复合材料的结构和性能进行表征. 结果表明, CdSe纳米粒子成功地吸附在Fe₃O₄纳米粒子表面, 并沿着c轴生长, 形成了宽3.6 nm, 长分别为14.5 和32.5 nm的新型枣核状和钉子状的异质结构体. 这种新型的Fe₃O₄-CdSe纳米复合材料是由磁铁矿Fe₃O₄和六方形的CdSe棒状结构组成, 具有较好的荧光性能和超顺磁性. 随着CdSe棒长度的增加, 荧光吸收峰向长波方向移动. Fe₃O₄纳米粒子, 枣核状和钉子状的Fe₃O₄-CdSe纳米复合材料的饱和磁化强度分别是57.80, 40.76和31.10 emu·g^-1.

Facile Fabrication of Novel Magnetic and Fluorescent Fe3O4-CdSe Nanocomposites

Novel Fe₃O₄-CdSe nanocomposites were prepared by depositing semiconductor on monodisperse magnetic nanoparticles. First, monodisperse Fe₃O₄ nanoparticles were fabricated by a solvothermal process in which iron acetylacetonate (Fe(acac)₃) was used as precursor, phenyl ether as reaction medium, oleic acid as surfactant and oleylamine (OAm) as both surfactant and reducing agent. Novel Fe₃O₄-CdSe heterostructures were prepared using 1-octadecene as high boiling solvent, cadmium oxide as Cd precursor, trioctyl phosphate (TOP)-Se as Se precursor, n-hexadecylamine (HDA) as surfactant, and stearic acid (SA) as growth promoter and nucleating agent. The structure and properties of the Fe₃O₄-CdSe nanocomposite were fully characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), UV-Vis spectrum, and photoluminescence (PL). CdSe nanoparticles were successfully attached to the surface of Fe₃O₄ and grew along the c-axis to form novel jujube pit-liked and nail-liked heterostructures with a width of 3.6 nm and length of 14.5 and 32.5 nm, respectively. The novel nanocomposites were a combination of magnetite Fe₃O₄ and hexagonal CdSe rods, and exhibited strong fluorescent emission without obvious quenching and excellent superparamagnetic properties. Fluorescent absorption shifts to longer wavelength as the length of the CdSe rods increases. The saturation magnetization of Fe₃O₄ nanoparticles, jujube pit liked and nail liked Fe₃O₄-CdSe nanocomposites were 57.80, 40.76, and 31.10 emu·g^-1, respectively.