Increasing the resolution of the scanning electrochemical microscope using a chemical lens: Application to silver deposition
Increasing the resolution of the scanning electrochemical microscope using a chemical lens: Application to silver deposition
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DOI：
10.1149/1.1392468
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发表时间：
1999-09-01
影响因子：
3.9
通讯作者：
Heinze, J
中科院分区：
文献类型：
--
作者：
Borgwarth, K;Heinze, J
与尖端产生的物质发生反应的清除剂的引入对扩散场产生了显着的聚焦效应。我们研究了这种新型扫描电化学显微镜操作模式（称为化学透镜）的基本原理。这种聚焦效应通过溶液中的银沉积得到证明，从而可以通过测量电流来直接监测样品表面的周转情况。在电解质溶液中，银阳离子与过量的氨络合，以避免银在金基材上沉积。使用该尖端电极，局部电产生的质子将复杂的形成平衡向后移动，产生更高浓度的游离银离子，随后在金覆盖的样品电极处放电。扩散场外层的游离银阳离子被过量的氨重新络合，氨作为清除剂，不参与沉积。分辨率达到低至不到有效裂口直径的三分之一。引入本身不参与电化学反应的清除剂代表了微电化学中缩小规模的通用方法。分辨率的提高不仅限于表面修饰，而且在表面分析中也被观察到。 (C) 1999 年电化学协会。 S0013-4651(98)11-089-3。版权所有。
The introduction of a scavenger that reacted with the tip-generated species produced a significant focusing effect on the diffusion field. We investigated the basic principles of this new scanning electrochemical microscope operating mode, called a chemical lens. This focusing effect was demonstrated by silver deposition from solution, which enabled direct monitoring of the turnover at the sample's surface by measuring the current. In the electrolyte solution, silver cations were complexed by an excess of ammonia to avoid initial silver deposition at the gold substrate. Using this tip electrode, locally electrogenerated protons shifted the complex Formation equilibrium back to produce higher concentrations of free silver ions, which were subsequently discharged at the gold-covered sample electrode. The free silver cations in the outer parr of the diffusion field were recomplexed by the excess of ammonia, which as it acted as a scavenger, did not take part in the deposition. The resolution reached values as low as less than one-third of the active rip diameter. The introduction of a scavenger which itself does not take part in electrochemical reactions represents a general method for downscaling in microelectrochemistry. The improvement in resolution is not restricted to surface modifications but has been observed in surface analysis as well. (C) 1999 The Electrochemical Society. S0013-4651(98)11-089-3. All rights reserved.