Facile synthesis of near-monodisperse Ag@Ni core–shell nanoparticles and their application for catalytic generation of hydrogen
Facile synthesis of near-monodisperse Ag@Ni core–shell nanoparticles and their application for catalytic generation of hydrogen
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DOI：
10.1088/0957-4484/22/19/195604
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发表时间：
2011-05
期刊：
影响因子：
3.5
通讯作者：
Huizhang Guo;Yuanzhi Chen;Xiaozhen Chen;R. Wen;G. Yue;D. Peng
中科院分区：
文献类型：
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作者：
Huizhang Guo;Yuanzhi Chen;Xiaozhen Chen;R. Wen;G. Yue;D. Peng
以油胺为溶剂和还原剂，三苯基膦为表面活性剂，采用一锅法合成了磁性可回收的Ag-Ni核壳纳米粒子。通过透射电子显微镜（TEM）表征，所合成的Ag-Ni核-壳纳米颗粒表现出非常窄的尺寸分布，典型尺寸为14.9 ± 1.2 nm，并且壳厚度可调。紫外-可见吸收光谱研究表明，在Ag核上形成Ni壳层可以抑制Ag核的表面等离子体共振（SPR），使SPR吸收峰发生红移。磁性测试表明，所合成的Ag-Ni核壳纳米粒子在室温下均具有超顺磁性，其阻断温度可以通过调节壳层厚度来控制。所合成的Ag-Ni核壳纳米粒子对硼氢化钠水溶液脱氢制H2反应表现出优异的催化性能。结果表明，Ag-Ni核壳纳米粒子的产氢速率远高于相同粒径的Ag和Ni纳米粒子，且其产氢活化能低于许多纳米粒子。该方法也可推广到其他贵磁金属体系。
Magnetically recyclable Ag–Ni core–shell nanoparticles have been fabricated via a simple one-pot synthetic route using oleylamine both as solvent and reducing agent and triphenylphosphine as a surfactant. As characterized by transmission electron microscopy (TEM), the as-synthesized Ag–Ni core–shell nanoparticles exhibit a very narrow size distribution with a typical size of 14.9 ± 1.2 nm and a tunable shell thickness. UV–vis absorption spectroscopy study shows that the formation of a Ni shell on Ag core can damp the surface plasmon resonance (SPR) of the Ag core and lead to a red-shifted SPR absorption peak. Magnetic measurement indicates that all the as-synthesized Ag–Ni core–shell nanoparticles are superparamagnetic at room temperature, and their blocking temperatures can be controlled by modulating the shell thickness. The as-synthesized Ag–Ni core–shell nanoparticles exhibit excellent catalytic properties for the generation of H2 from dehydrogenation of sodium borohydride in aqueous solutions. The hydrogen generation rate of Ag–Ni core–shell nanoparticles is found to be much higher than that of Ag and Ni nanoparticles of a similar size, and the calculated activation energy for hydrogen generation is lower than that of many bimetallic catalysts. The strategy employed here can also be extended to other noble-magnetic metal systems.