Smart and Reversible Surface Plasmon Resonance Responses to Various Atmospheres for Silver Nanoparticles Loaded in Mesoporous SiO2

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• 作者：Jinlian Hu ; Li Wang ; Weiping Cai ; Yue Li ; Haibo Zeng ; Lanqiang Zhao ; Peisheng Liu
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：November 5, 2009
• 年：2009
• 卷：113
• 期：44
• 页码：19039-19045
• 全文大小：219K
• 年卷期：v.113,no.44(November 5, 2009)
• ISSN：1932-7455

文摘

The surface plasmon resonance (SPR) optical absorption of Ag nanoparticles loaded in mesoporous SiO₂ (with fairly low Ag content, about 0.14 wt %) have been investigated after the nanoparticles were heated in or exposed to various atmospheres (i.e., air, H₂, water vapor, Ar, and H₂S). Unexpectedly, the SPR optical absorption can completely disappear in quite a short time or intensively emerge or drastically change into semiconductor optical absorption edge. Surprisingly, the SPR switches are well reversible and very rapid when alternating treatment of samples in any two atmospheres mentioned above. In addition, those novel and distinctive SPR changes reflect a series of abnormal chemical redox behaviors in various atmospheres. The mechanisms have been discussed based on modeling multi-interactions between the mesoporous SiO₂ matrix, Ag nanoparticles, and atmospheres, revealing a special surface/interface synergetic effect that induces many novel phenomena despite SiO₂ usually being regarded as a chemical inert medium to noble metals and environmental atmospheres. Our new findings for such a simple Ag/SiO₂ system, smart, reversible, and rapid SPR responses to various atmospheres, are highly valuable for SPR gas sensor, optical switch, and other SPR optics and give a new understanding of the catalysis and surface/interface chemistry in the Ag/SiO₂ system.