Fe_3O_4@Au核壳结构的制备及在苯乙烯环氧化中的研究

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.

The Preparation of Fe3O4@Au Core-Shell Structure Materials and Its Application in Epoxidation of Styrene

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.