Facile synthesis of nanostructured gold for microsystems by the combination of electrodeposition and dealloying
Facile synthesis of nanostructured gold for microsystems by the combination of electrodeposition and dealloying
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DOI：
10.1039/c1jm10435g
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发表时间：
2011-06
影响因子：
--
通讯作者：
Satoshi Tominaka
中科院分区：
文献类型：
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作者：
Satoshi Tominaka
微集电体上多孔电极的合成对于微传感器、微燃料电池等微电化学系统的成功开发具有重要意义。本文提出了一种基于电沉积和去合金化相结合的简便的电化学方法。在含有铜离子和四氯金酸盐的硫酸溶液中沉积Au-Cu合金，然后在相同的溶液中施加更正的电位进行脱合金化。所合成的薄膜为100at%的多晶金，由海绵状纳米结构组成，韧带厚度为50-100 nm，气孔较宽。根据X射线光电子能谱和电子衍射仪的结果，发现韧带表面的晶格收缩。这可能是由于脱合金化产生的残余应力所致。电化学测试表明，该膜的比表面积约为其几何面积(厚度为780 nm)的25倍，且表面含有有序的大的Au(111)阶梯。最后，利用微电极阵列验证了该合成方法在微系统中应用的可行性。因此，该方法有望用于制备微电化学器件用的金电极。
For the successful exploitation of microelectrochemical systems, e.g., micro-sensors and micro-fuel cells, synthesis of porous electrodes on tiny current collectors is of great importance. Here, a facile electrochemical method based on the combination of electrodeposition and dealloying is proposed. AuCu alloy was deposited in a sulfuric acid solution containing cupric ions and tetrachloroaurate ions, and then was dealloyed in the same solution just by applying a more positive potential. The synthesized thin film was 100 at% polycrystalline Au and consisted of spongelike nanostructures with 50–100 nm thick ligaments and wider pores. The crystal lattice of the ligament surface was found to be contracted on the basis of the results of X-ray photoelectron spectroscopy and electron diffractometry. This is probably due to the residual stress caused by dealloying. The electrochemical measurements revealed that the surface area was ca. 25 times larger than its geometrical area (thickness: 780 nm), and that the surface contained well-ordered large Au(111) terraces. Finally, feasibility of the application of this synthesis to microsystems was proved by using microelectrode arrays. Thus, this method is promising for preparing Au electrodes for microelectrochemical devices.