Research Institute of Applied Catalysis, Shanghai Institute of Technology, Shanghai 201418, China.
Molecules. 2013 Nov 18;18(11):14258-67. doi: 10.3390/molecules181114258.
Fe3O4 spheres with an average size of 273 nm were prepared in the presence of CTAB by a solvothermal method. The spheres were modified by a thin layer of SiO2, and then coated by mesoporous SiO2 (m-SiO2) films, by using TEOS as a precursor and CTAB as a soft template. The resulting m-SiO2/Fe3O4 spheres, with an average particle size of 320 nm, a high surface area (656 m2/g), and ordered nanopores (average pore size 2.5 nm), were loaded with gold nanoparticles (average size 3.3 nm). The presence of m-SiO2 coating could stabilize gold nanoparticles against sintering at 500 °C. The material showed better performance than a conventional Au/SiO2 catalyst in catalytic reduction of p-nitrophenol with NaBH4. It can be separated from the reaction mixture by a magnet and be recycled without obvious loss of catalytic activity. Relevant characterization by XRD, TEM, N2 adsorption-desorption, and magnetic measurements were conducted.
在 CTAB 的存在下，通过溶剂热法制备了平均尺寸为 273nm 的 Fe3O4 球体。这些球体通过一层薄的 SiO2 进行了修饰，然后通过使用 TEOS 作为前体和 CTAB 作为软模板，涂覆了介孔 SiO2（m-SiO2）膜。得到的 m-SiO2/Fe3O4 球体，平均粒径为 320nm，具有高比表面积（656m2/g）和有序的纳米孔（平均孔径为 2.5nm），负载了金纳米粒子（平均尺寸为 3.3nm）。m-SiO2 涂层的存在可以稳定金纳米粒子，防止它们在 500°C 下烧结。与传统的 Au/SiO2 催化剂相比，该材料在使用 NaBH4 催化还原对硝基苯酚时表现出更好的性能。它可以通过磁铁从反应混合物中分离出来，并在没有明显失活的情况下回收利用。进行了相关的 XRD、TEM、N2 吸附-脱附和磁测量表征。
