Syntheses of Ag-Au and Ag-Pd Alloy Triangular Hollow Nanoframes by Galvanic Replacement Reactions without and with Post-treatment Using NaCl in an Aqueous Solution
Syntheses of Ag-Au and Ag-Pd Alloy Triangular Hollow Nanoframes by Galvanic Replacement Reactions without and with Post-treatment Using NaCl in an Aqueous Solution
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通过电置换反应合成银-金和银-钯合金三角形空心纳米框架，无需和在水溶液中使用 NaCl 进行后处理
DOI：
10.1039/c3ce42244e
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发表时间：
2014
期刊：
影响因子：
3.1
通讯作者：
and Hirofumi Kawazumi
中科院分区：
文献类型：
--
作者：
Masaharu Tsuji;Takafumi Kidera;Atsuhiko Yajima;Mika Hamasaki;Masashi Hattori;Takeshi Tsuji;and Hirofumi Kawazumi
利用Ag纳米棱柱与HAuCl 4和Na 2 PdCl 4在水溶液中的电置换反应制备了Ag-Au和Ag-Pd合金三角形中空纳米框架。通过透射电子显微镜（TEM）和TEM-能量色散X射线能谱（EDS）、X射线衍射（XRD）和紫外（UV）-可见（维斯）-近红外（NIR）消光光谱数据研究了它们的生长机理。结果表明，Ag-Au合金三角形框架首先形成一个截顶棱柱，然后空心结构向棱柱内部膨胀，再形成三角形，最后在室温下在几分钟内形成三角形框架。另一方面，通过加入Na 2 PdCl 4并在100 °C下加热30-120 min，可以缓慢地形成三角形的Ag-Pd合金片。结果表明，用饱和NaCl溶液进行后处理可以有效地将Ag-Pd合金纳米片转变为Ag-Pd纳米框架。纳米框架形成的差异可以通过AuCl 4 −的Ag-Au合金和Pd 2+的Ag-Pd合金之间的脱合金速率的差异来解释。XRD数据表明，六方密堆积（hcp）层作为三角形的Ag-Au和Ag-Pd合金纳米框架的主要成分。
Ag–Au and Ag–Pd alloy triangular hollow nanoframes were prepared using galvanic replacement (GR) reactions of Ag nanoprisms with HAuCl4 and Na2PdCl4 in an aqueous solution. Their growth mechanisms were studied by observing transmission electron microscopic (TEM) and TEM-energy dispersed X-ray spectroscopic (EDS), XRD, and ultraviolet (UV)-visible (Vis)-near infrared (NIR) extinction spectral data. Results show that Ag–Au alloy triangular frames start with formation of a truncated prism, followed by expansion of a hollow structure to the interior of the prism, reformation of the triangular shape, and finally formation of a triangular frame at ambient temperature within a few minutes. On the other hand, triangular Ag–Pd alloy plates are slowly formed by the addition of Na2PdCl4 and heating at 100 °C for 30–120 min. Results show that post-treatment using saturated NaCl solution is effective for the transformation of Ag–Pd alloy nanoplates to Ag–Pd nanoframes. The difference in the formation of nanoframes is explained by the difference in the dealloying rates between Ag–Au alloys by AuCl4− and Ag–Pd alloys by Pd2+. XRD data suggested that hexagonally closed packed (hcp) layers are involved as major components of the triangular Ag–Au and Ag–Pd alloy nanoframes.