Formation of AgPt Alloy Nanoislands via Chemical Etching with Tunable Optical and Catalytic Properties

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• 作者：Weiwei He ; Xiaochun Wu ; Jianbo Liu ; Ke Zhang ; Weiguo Chu ; Lili Feng ; Xiaona Hu ; Weiya Zhou ; Sishen Xie
• 刊名：Langmuir
• 出版年：2010
• 出版时间：March 16, 2010
• 年：2010
• 卷：26
• 期：6
• 页码：4443-4448
• 全文大小：945K
• 年卷期：v.26,no.6(March 16, 2010)
• ISSN：1520-5827

文摘

An effective way is developed to fabricate AgPt alloy nanoislands on gold nanorods based on the galvanic replacement between Ag and PtCl₄²⁻ in the presence of cetyltrimethylammonium bromide (CTAB). The optical and catalytic properties benefit from the porous structure composed of AgPt nanoislands. A large red shift (265 nm) after etching is observed for longitudinal surface plasmon resonance (SPR) in comparison with Au@Pt0.1@Ag. Alloy compositions in bulk miscibility gap can be obtained and finely tuned from Ag_0.56Pt_0.44 to Ag_0.38Pt_0.62. A unique composition dependence is found for both electrocatalytic oxidation of methanol and catalytic oxidation of o-phenylenediamine (OPD) by hydrogen peroxide. In both systems, the highest catalytic activity is achieved at the alloy composition of Pt_0.62Ag_0.38. Proper alloying with Ag not only improves the CO poisoning of Pt catalyst but also enhances the catalytic activity greatly.