Shielding effect of double microelectrode tips in a scanning electrochemical microscope
Shielding effect of double microelectrode tips in a scanning electrochemical microscope
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DOI：
10.1016/j.electacta.2011.01.103
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发表时间：
2011-11-01
影响因子：
6.6
通讯作者：
Hasegawa, Yasuchika
中科院分区：
文献类型：
--
作者：
Fushimi, Koji;Matsushita, Ken-ichiro;Hasegawa, Yasuchika
研究了同轴双微电极（一个微电极被另一个微电极包围）的电化学相互作用。发生在内外微电极上的传质反应相互干扰，并表现出“屏蔽”效应，这取决于电位和微电极的几何形状。将双微电极中的内微电极应用于扫描电化学显微镜（SECM）的探针，发现外微电极的屏蔽效应影响了内微电极在基底表面附近的电化学行为。在SECM的反馈模式下，随着微电极的靠近，绝缘体上方的影响增强，而导体上方的影响减弱。接近一个临界极间距离也加强了在基板生成/尖端收集模式的屏蔽效果。采用铂/环氧树脂模型衬底进行了SECM线扫描，研究了屏蔽对SECM图像电流灵敏度和横向分辨率的影响。(C)2011爱思唯尔有限公司保留所有权利。
Electrochemical interaction of coaxial double microelectrodes, in which a ring microelectrode was surrounded by another ring microelectrode, was investigated. Mass-transfer reactions that occurred on both inner and outer microelectrodes interfered with each other and showed a "shielding" effect depending on potentials and geometries of microelectrodes. Application of the inner microelectrode of the double microelectrodes for a probing tip of a scanning electrochemical microscope (SECM) revealed that the shielding effect by the outer microelectrode affected the electrochemistry on the inner microelectrode in the vicinity of the substrate surface. The effect was intensified above the insulator but attenuated above the conductor as the microelectrodes approached in feedback mode of the SECM. Approach to a critical interelectrode distance also intensified the shielding effect in the substrate generation/tip collection mode. An SECM line-scan using a platinum/epoxy resin-model substrate was carried out to investigate the shielding effect on current sensitivity and lateral resolution of an SECM image. (C) 2011 Elsevier Ltd. All rights reserved.