Synthesis of Water Dispersible and Catalytically Active Gold-Decorated Cobalt Ferrite Nanoparticles

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• 作者：Alessandro Silvestri ; Sara Mondini ; Marcello Marelli ; Valentina Pifferi ; Luigi Falciola ; Alessandro Ponti ; Anna Maria Ferretti ; Laura Polito
• 刊名：Langmuir
• 出版年：2016
• 出版时间：July 19, 2016
• 年：2016
• 卷：32
• 期：28
• 页码：7117-7126
• 全文大小：616K
• 年卷期：0
• ISSN：1520-5827

文摘

Hetero-nanoparticles represent an important family of composite nanomaterials that in the past years are attracting ever-growing interest. Here, we report a new strategy for the synthesis of water dispersible cobalt ferrite nanoparticles (Co_xFe_3–xO₄ NPs) decorated with ultrasmall (2–3 nm) gold nanoparticles (Au NPs). The synthetic procedure is based on the use of 2,3-meso-dimercaptosuccinic acid (DMSA), which plays a double role. First, it transfers cobalt ferrite NPs from the organic phase to aqueous media. Second, the DMSA reductive power promotes the in situ nucleation of gold NPs in proximity of the magnetic NP surface. Following this procedure, we achieved a water dispersible nanosystem (Co_xFe_3–xO₄–DMSA–Au NPs) which combines the cobalt ferrite magnetic properties with the catalytic features of ultrasmall Au NPs. We showed that Co_xFe_3–xO₄–DMSA–Au NPs act as an efficient nanocatalyst to reduce 4-nitrophenol to 4-aminophenol and that they can be magnetically recovered and recycled. It is noteworthy that such nanosystem is more catalytically active than Au NPs with equal size. Finally, a complete structural and chemical characterization of the hetero-NPs is provided.