Bifunctional Au-Fe3O4 Heterostructures for Magnetically Recyclable Catalysis of Nitrophenol Reduction
Bifunctional Au-Fe3O4 Heterostructures for Magnetically Recyclable Catalysis of Nitrophenol Reduction
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DOI：
10.1021/jp110956k
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发表时间：
2011-04-14
影响因子：
3.7
通讯作者：
Doong, Ruey-an
中科院分区：
文献类型：
--
作者：
Lin, Fang-hsin;Doong, Ruey-an
以不同粒径的Au纳米颗粒为晶种，利用磁性可循环催化对硝基苯酚和2，4-二硝基苯酚的还原反应，成功地制备了油酸铁络合物在Au纳米颗粒存在下的热分解哑铃状和花朵状Au-Fe3O4异质结构。该异质结构具有较高的磁化强度和良好的对硝基苯酚还原反应的催化活性。哑铃状和花状异质结构中的外延键不同，导致了异质结构纳米催化剂的磁性和催化性能的变化。哑铃型和花状Au-Fe3O4异质结对硝基苯酚还原的准一级反应速率常数分别为0.63-0.72min(-1)和0.38-0.46min(-1)。此外，异质结构纳米催化剂表现出良好的分离能力和重复使用能力，可重复使用至少6个连续循环，几乎完全还原硝基苯酚。提出了Au-Fe3O4纳米催化剂还原硝基苯酚的反应机理，并通过XPS和FTIR分析证实了反应机理。这些独特的性质使Au-Fe3O4异质结构成为研究各种多相催化过程的理想平台，在净化、催化、传感器件和绿色化学等领域具有广泛的应用前景。
The dumbbell- and flower-like Au-Fe3O4 heterostructures by thermal decomposition of the iron oleate complex in the presence of Au nanoparticles (NPs) have been successfully fabricated using different sizes of Au NPs as the seeds for magnetically recyclable catalysis of p-nitrophenol and 2,4-dinitrophenol reduction. The heterostructures exhibit bifunctional properties with high magnetization and excellent catalytic activity toward nitrophenol reduction. The epitaxial linkages in dumbbell- and flower-like heterostructures are different, leading to the change in magnetic and catalytic properties of the hetero-structured nanocatalysts. The pseudo-first-order rate constants for nitrophenol reduction are 0.63-0.72 min(-1) and 0.38-0.46 min(-1) for dumbbell- and flower-like Au-Fe3O4 heterostructures, respectively. In addition, the heterostructured nanocatalysts show good separation ability and reusability which can be repeatedly applied for nearly complete reduction of nitrophenols for at least six successive cycles. The reaction mechanism for nitrophenol reduction by Au-Fe3O4 nanocatalysts is also proposed and confirmed by XPS and FTIR analyses. These unique properties make Au-Fe3O4 heterostructures an ideal platform to study various heterogeneous catalytic processes which can be potentially applied in a wide variety of fields in purification., catalysis, sensing devices, and green chemistry.