In situ growth of gold nanoparticles onto polydopamine-encapsulated magnetic microspheres for catalytic reduction of nitrobenzene
In situ growth of gold nanoparticles onto polydopamine-encapsulated magnetic microspheres for catalytic reduction of nitrobenzene
复制标题
金纳米粒子在聚多巴胺封装的磁性微球上原位生长用于催化还原硝基苯
DOI：
10.1016/j.apcatb.2012.12.037
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发表时间：
2013-05-02
影响因子：
22.1
通讯作者：
Cai, Ya-qi
中科院分区：
文献类型：
--
作者：
Zeng, Tao;Zhang, Xiao-le;Cai, Ya-qi
为了制备核壳结构的Fe3O4@PDA-Au纳米催化剂，提出了一种在聚多巴胺(PDA)包裹的Fe3O4纳米粒子表面沉积金纳米粒子(Au NPs)的方法。在目前的方法中，将直径约400 nm的Fe3O4核心包裹在厚度约为45 nm的PDA涂层中，然后在涂层上固定大量细小的Au纳米粒子。PDA既是一种还原剂，也是一种稳定剂，因此不需要额外的试剂和热处理。此外，Au纳米颗粒的尺寸和PDA层的厚度都是可调的，以在PDA涂层上负载更多尺寸合适的Au纳米颗粒。Fe3O4@PDA-Au纳米复合材料的Au含量约为4.3wt.%，对NaBH4还原邻硝基苯胺合成苯二胺具有良好的催化性能(7min内转化率可达99%)。最重要的是，由于高磁化强度(39.6emu g(-1))，催化剂可以很容易地通过使用外部磁场进行回收，并且表现出良好的重复使用性能(8个循环，邻硝基苯胺的转化率为>；98%)。所制备的催化剂对其他硝基苯类化合物的还原也表现出良好的活性。这些都有利于该催化剂在硝基芳香族化合物还原反应中的实际应用。(C)2013爱思唯尔B.V.保留所有权利。
A simple and green method for the deposition of gold nanoparticles (Au NPs) on the surface of polydopamine (PDA)-encapsulated Fe3O4 nanoparticles is proposed to fabricate a core-shell Fe3O4@PDA-Au nanocatalyst. In the current approach, Fe3O4 core, about 400 nm in diameter, is enveloped in a PDA coating with a thickness of about 45 nm on which plenty of small Au NPs are immobilized subsequently. PDA serves as a reductant as well as a stabilizer so that additional reagents and thermo treatment are not necessary. In addition, both the size of Au NPs and the thickness of PDA layer are tunable to load more Au NPs with appropriate size on the PDA coating. The Au content on Fe3O4@PDA-Au nanocomposites is about 4.3 wt.%, which endows the nanocatalyst with high catalytic performance in the reduction of o-nitroaniline to benzenediamine by NaBH4 (with a conversion of 99% in 7 min). Most importantly, the catalyst can be easily recycled by using an external magnetic field due to the high magnetization (39.6 emu g(-1)) and shows excellent reusability (8 cycles with a conversion of >98% for o-nitroaniline). The as-prepared catalyst also show good activity for the reduction of other nitrobenzene analogs. These facilitate the practical application of the catalyst in reduction of nitroaromatic compounds. (c) 2013 Elsevier B.V. All rights reserved.