Synthesis of double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres and their catalytic applications
Synthesis of double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres and their catalytic applications
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DOI：
10.1088/0957-4484/26/9/095601
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发表时间：
2015-03
期刊：
影响因子：
3.5
通讯作者：
Jie Li;Li Tan;Ge Wang;Mu Yang
中科院分区：
文献类型：
--
作者：
Jie Li;Li Tan;Ge Wang;Mu Yang
采用NaBH 4水溶液原位还原HAuCl 4，在Fe 3 O 4/TiO 2载体上负载Au纳米粒子，成功制备了双壳海胆状Fe 3 O 4/TiO 2/Au微球。这些微球具有可调的腔尺寸、可调的壳层厚度、高的结构稳定性和大的比表面积。将直径约为5 nm的Au纳米粒子负载在TiO 2纳米纤维上和海胆状蛋黄壳Fe 3 O 4/TiO 2微球的空腔内。TiO 2纳米纤维组成的海胆状结构保证了Au纳米粒子的良好分布，而新颖的双壳蛋黄壳结构保证了Au纳米粒子的高稳定性。此外，Fe 3 O 4磁芯有助于通过施加外部磁场方便地回收催化剂。Fe 3 O 4/TiO 2/Au微球在催化还原4-硝基苯酚（4-NP）反应中表现出优异的活性和循环性能：反应速率常数为1.84 min-1，转化频率为5457 h-1。
Double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres were successfully synthesized through loading Au nanoparticles on the Fe3O4/TiO2 support by a in situ reduction of HAuCl4 with NaBH4 aqueous solution. These microspheres possess tunable cavity size, adjustable shell layers, high structural stability and large specific surface area. The Au nanoparticles of approximately 5 nm in diameter were loaded both on the TiO2 nanofibers and inside the cavities of sea urchin-like yolk-shell Fe3O4/TiO2 microspheres. The sea urchin-like structure composed of TiO2 nanofibers ensure the good distribution of the Au nanoparticles, while the novel double-shelled yolk-shell structure guarantees the high stability of the Au nanoparticles. Furthermore, the Fe3O4 magnetic core facilitates the convenient recovery of the catalyst by applying an external magnetic field. The Fe3O4/TiO2/Au microspheres display excellent activities and recycling properties in the catalytic reduction of 4-nitrophenol (4-NP): the rate constant is 1.84 min−1 and turnover frequency is 5457 h−1.