Structural rearrangement of bimetallic alloy PdAu nanoparticles within dendrimer templates to yield core/shell configurations

被引:142
作者
Knecht, Marc R. [2 ]
Weir, Michael G. [2 ]
Frenkel, Anatoly I. [1 ]
Crooks, Richard M. [2 ]
机构
[1] Yeshiva Univ, Dept Phys, New York, NY 10016 USA
[2] Univ Texas Austin, Univ Stn 1, Ctr Nano & Mol Sci & Technol, Texas Mat Inst,Dept Chem & Biochem, Austin, TX 78712 USA
关键词
D O I
10.1021/cm0717817
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Here we present evidence for an oxidation-driven structural conversion of quasi-alloy PdAu dendrimer-encapsulated nanoparticles (DENs) to a Au-core/Pd-sbell configuration. The initial quasialloy was prepared by co-complexation of PdCl42- and AuCl4- within a sixth-generation, poly(amidoamine) dendrimer template followed by chemical reduction. Exposure to air resulted in selective reoxidation of the Pd atoms and subsequent re-reduction led to deposition of a Pd-rich shell on the surface of the remaining Art core. The core/shell nanoparticles were extracted as monolayer-protected clusters (MPCs) from within the dendrimer templates using dodecanethiol. The resulting materials were characterized by UV-vis spectroscopy, transmission electron microscopy, and extended X-ray absorption fine structure (EXAFS) spectroscopy.
引用
收藏
页码:1019 / 1028
页数:10
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