Fe_3O_4@Au核壳结构的制备及在苯乙烯环氧化中的研究

The Preparation of Fe_3O_4@Au Core-Shell Structure Materials and Its Application in Epoxidation of Styrene

以FeCl3·6H2O为铁源,乙二醇为还原剂,聚乙二醇为表面活性剂,在200℃水热条件下制备平均粒径约为300 nm的介孔Fe3O4.以3-氨丙基三乙氧基硅烷(APTES)为偶联剂对Fe3O4进行改性,室温超声下用柠檬酸钠将Au3+还原为Au0,制备了Fe3O4@Au核壳材料.利用扫描电镜(SEM),N2-吸附-脱附等温线,X射线衍射(XRD),傅里叶变换红外对核壳材料进行表征,结果表明,比表面为95.56 m2/g、孔径为5.67 nm,Fe3O4表面被金均匀涂层,其具有较好的光催化环氧化选择性.

Mesoporous magnetic iron oxide （Fe3O4） nanospheres with average particle size of approximately 300 nm were synthesized using hydrothermal method at 200 ℃,using ferric chloride hexahydrate（FeCl3·6H2O）as iron source,ethylene glycol as the reducing agent,polyethylene glycol（PEG）as the surfactant. Then the Fe3O4 nanoparticles were chemically modified by using 3-aminopropyltriethoxysilane（APTES） as silylation reagent. Subsequently,the well-defined mesoporous Fe3O4（core）@Au（shell） structures nanospheres with high monodispersity were obtained under ultrasonic at room temperature with sodium citrate adding dropwise as the reducing agent for reducing Au^3＋ to Au0. The morphology and crystal structure of the as-prepared nanocomposites were characterized by scanning electronic microscopy（SEM）,N2 adsorption-desorption isotherms,X-ray powder diffraction（XRD）patterns,Fourier transform infrared（FT-IR）spectroscopy et al. The results showed that the surface area of Fe3O4 nanoparticle and the nanospheres diameter prepared using the method were 95.56m^2/g and 5.67 nm,respectively. Besides,the spherical central Fe3O4 cores were coated by a uniform Au layer. Furthermore,the nanocomposites has a good effect on selectivity photocatalytic epoxidation.