Heterogeneous silver–polyaniline nanocomposites with tunable morphology and controllable catalytic properties
Heterogeneous silver–polyaniline nanocomposites with tunable morphology and controllable catalytic properties
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DOI：
10.1088/0957-4484/24/18/185602
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发表时间：
2013-05
期刊：
影响因子：
3.5
通讯作者：
C. Yuan;Yiting Xu;Lina Zhong;Long Zhang;Cangjie Yang;Binjie Jiang;Yuanming Deng;Birong Zeng;N. He;W. Luo;L. Dai
中科院分区：
文献类型：
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作者：
C. Yuan;Yiting Xu;Lina Zhong;Long Zhang;Cangjie Yang;Binjie Jiang;Yuanming Deng;Birong Zeng;N. He;W. Luo;L. Dai
本文不仅介绍了一种简单的水热法制备形态可控的银-聚苯胺(Ag-PANI)纳米复合材料，而且还介绍了一种具有可调谐和可切换催化能力的催化剂。在不同的水热温度下，成功地制备了Ag-PANI Janus纳米粒子(NPs)和Ag@PANI核壳纳米粒子。通过调整加料比，微调了Janus NPs的Ag和PANI两个半球的直径，以及核壳NPs的PANI壳厚度。以对硝基苯(NB)和对硝基苯酚(4-NP)的催化还原为模型反应，对PANI组分在多相催化剂催化性能中的作用进行了深入的研究。结果表明，PANI纳米复合材料的催化性能依赖于PANI的形态和疏水性。在Ag纳米粒子表面包覆PANI壳层可以使亲脂性的Nb聚集，从而提高了Ag@PANI核壳纳米粒子的催化性能。然而，当Ag-PANI Janus NPs催化还原Nb时，并没有观察到这种催化能力的增强。更重要的是，核壳纳米粒子对亲水性4-NP还原的催化能力可以通过改变PANI壳层从未掺杂状态到掺杂状态来切换。
This paper introduces not only a simple hydrothermal route to silver–polyaniline (Ag–PANI) nanocomposites with controllable morphology, but also a type of catalyst possessing tunable and switchable catalytic capability. Ag–PANI Janus nanoparticles (NPs) and Ag@PANI core–shell NPs have been constructed successfully at different hydrothermal temperatures. The diameter of both Ag and PANI hemispheres of Janus NPs, as well as the PANI shell thickness of core–shell NPs, was finely tuned via adjustment of the feed ratio. We also gained a deeper insight into the functionalities of PANI components in the catalytic capability of the heterogeneous catalysts, choosing catalytic reductions of nitrobenzene (NB) and 4-nitrophenol (4-NP) as model reactions. Our results showed that the catalytic capability of the nanocomposites was dependent on the PANI morphology and hydrophobicity. The PANI shell coating on Ag NPs can concentrate the lipophilic NB, thus leading to an enhanced catalytic capability of Ag@PANI core–shell NPs. However, this enhanced catalytic capability was not observed for Ag–PANI Janus NPs when catalytically reducing NB. More importantly, the catalytic capability of the core–shell NPs in the reduction of hydrophilic 4-NP is switchable by varying the PANI shell from an undoped to a doped state.