Alloying and dealloying processes involved in the preparation of metal nanoshells through a galvanic replacement reaction
Alloying and dealloying processes involved in the preparation of metal nanoshells through a galvanic replacement reaction
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DOI：
10.1021/nl034765r
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发表时间：
2003-11-01
期刊：
影响因子：
10.8
通讯作者：
Xia, YN
中科院分区：
文献类型：
--
作者：
Sun, YG;Xia, YN
Ag纳米颗粒和HAuCl 4水溶液之间的电流置换反应最近已被证明是获得具有中空内部和高度结晶壁的金属纳米结构的简单且方便的途径（参见例如Sun，Y.;梅耶，B。T.; Xia，Y. Nano Lett. 2002，2，481.孙，Y.; Xia，Y. Science，2002，298，2176）。然而，这个模板参与反应的整个过程中所涉及的形态，成分，结构和光谱变化的细节还有待阐明。在这封信中描述的实验结果表明，模板过程进行通过两个不同的步骤：（i）形成无针孔的纳米壳均匀，均匀的壁Au/Ag合金通过置换反应和合金化的组合;和（ii）多孔纳米壳（纳米笼）通过脱合金过程，其中Ag被选择性地溶解从由Au/Ag合金制成的壁形成。随着合金化和去合金化的进行，所得到的金属纳米结构的表面等离子体共振峰可以从近似425 nm连续调谐到近似1030 nm。
The galvanic replacement reaction between Ag nanoparticles and an aqueous HAuCl4 solution has recently been demonstrated as a simple and convenient route to metal nanostructures with hollow interiors and highly crystalline walls (see, for example, Sun, Y.; Mayers, B. T.; Xia, Y. Nano Lett. 2002, 2, 481. Sun, Y.; Xia, Y. Science, 2002, 298, 2176). However, the details of morphological, compositional, structural, and spectral changes involved in the entire process of this template-engaged reaction is yet to be elucidated. The experimental results described in this letter indicate that the templating process proceeded through two distinctive steps: (i) formation of pinhole-free nanoshells with homogeneous, uniform walls of Au/Ag alloys via a combination of the replacement reaction and alloying; and (ii) formation of porous nanoshells (nanocages) through a dealloying process, in which Ag was selectively dissolved from the walls made of Au/Ag alloys. As alloying and dealloying proceeded, the surface plasmon resonance peaks of resultant metal nanostructures could be continuously tuned from similar to425 to similar to1030 nm.