Fabrication of cubic nanocages and nanoframes by dealloying Au/Ag alloy nanoboxes with an aqueous etchant based on Fe(NO3)3 or NH4OH
Fabrication of cubic nanocages and nanoframes by dealloying Au/Ag alloy nanoboxes with an aqueous etchant based on Fe(NO3)3 or NH4OH
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DOI：
10.1021/nl070838l
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发表时间：
2007-06-01
期刊：
影响因子：
10.8
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
Lu, Xianmao;Au, Leslie;Xia, Younan
本文介绍了一个两步程序生成立方纳米笼和纳米框架。在第一步中，通过Ag纳米立方体与HAuCl 4水溶液之间的电置换反应合成Au/Ag合金纳米盒。第二步涉及用基于Fe（NO3）（3）或NH 4 OH的水性蚀刻剂从合金纳米盒中选择性地去除（或脱合金化）Ag。使用除HAuCl 4之外的湿法蚀刻剂用于脱合金工艺允许更好地控制所得纳米笼的壁厚和孔隙率，因为不存在Au的同时沉积。通过增加Fe（NO3）（3）或NH 4 OH加入到脱合金过程中的量，来自50 nm银纳米立方体的纳米盒可以转化为纳米笼，然后是具有表面等离子体共振（SPR）峰从可见光区连续移动到1200 nm的立方纳米框架。还可以通过控制用于电置换反应的HAuCl 4的量并因此优化合金纳米盒中Au的百分比来获得具有相对窄的SPR峰（半峰全宽小至180 nm）的纳米笼。
This paper describes a two-step procedure for generating cubic nanocages and nanoframes. In the first step, Au/Ag alloy nanoboxes were synthesized through the galvanic replacement reaction between Ag nanocubes and an aqueous HAuCl4 solution. The second step involved the selective removal (or dealloying) of Ag from the alloy nanoboxes with an aqueous etchant based on Fe(NO3)(3) or NH4OH. The use of a wet etchant other than HAuCl4 for the dealloying process allows one to better control the wall thickness and porosity of resultant nanocages because there is no concurrent deposition of Au. By increasing the amount of Fe(NO3)(3) or NH4OH added to the dealloying process, nanoboxes derived from 50-nm Ag nanocubes could be converted into nanocages and then cubic nanoframes with surface plasmon resonance (SPR) peaks continuously shifted from the visible region to 1200 nm. It is also possible to obtain nanocages with relatively narrow SPR peaks (with a full width at half-maximum as small as 180 nm) by controlling the amount of HAuCl4 used for the galvanic replacement reaction and thus the optimization of the percentage of Au in the alloy nanoboxes.