Synthesis of Size-Controlled Faceted Pentagonal Silver Nanorods with Tunable Plasmonic Properties and Self-Assembly of These Nanorods

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• 作者：Brendan Pietrobon ; Matthew McEachran ; Vladimir Kitaev
• 刊名：ACS Nano
• 出版年：2009
• 出版时间：January 27, 2009
• 年：2009
• 卷：3
• 期：1
• 页码：21-26
• 全文大小：447K
• 年卷期：0
• ISSN：1936-086X

文摘

Monodisperse size-controlled faceted pentagonal silver nanorods were synthesized by thermal regrowth of decahedral silver nanoparticle (AgNPs) in aqueous solution at 95 °C, using citrate as a reducing agent. The width of the silver nanorods was determined by the size of the starting decahedral particle, while the length was varied from 50 nm to 2 μm by the amount of new silver added to the growth solution. Controlled regrowth allowed us to produce monodisperse AgNPs with a shape of elongated pentagonal dipyramid (regular Johnson solid, J₁₆). Faceted pentagonal particles exhibited remarkable optical properties with sharp plasmon resonances precisely tunable across visible and NIR. Due to the narrow size distribution, faceted pentagonal silver nanorods readily self-assembled into the 3-D arrays similar to smectic mesophases. Hexagonal arrangement in the array completely overrode five-fold symmetry of the nanorods. Overall, our findings highlight the importance of pentagonal symmetry in metal nanoparticles and offer a facile method of the preparation of monodisperse AgNPs with controlled dimensions and plasmonic properties that are promising for optical applications and functional self-assembly.