Facile Fabrication of Novel Magnetic and Fluorescent Fe<sub>3</sub>O<sub>4</sub>-CdSe Nanocomposites

Abstract

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.