PASSIVATION OF PINHOLES IN OCTADECANETHIOL MONOLAYERS ON GOLD ELECTRODES BY ELECTROCHEMICAL POLYMERIZATION OF PHENOL
PASSIVATION OF PINHOLES IN OCTADECANETHIOL MONOLAYERS ON GOLD ELECTRODES BY ELECTROCHEMICAL POLYMERIZATION OF PHENOL
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DOI：
10.1021/la00092a014
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发表时间：
1990-02-01
期刊：
影响因子：
3.9
通讯作者：
FEDYK, J
中科院分区：
文献类型：
--
作者：
FINKLEA, HO;SNIDER, DA;FEDYK, J
金电极上有组织的十八烷硫醇单层强烈抑制法拉第反应，但单层中的针孔除外。对于简单的外球氧化还原电对，单层涂层电极的行为类似于微电极阵列，其中针孔充当微电极。针孔的平均尺寸和间距可以通过将实验循环伏安图与微阵列电极的模拟伏安图拟合来估计。通过苯酚在稀硫酸中的电化学聚合，针孔被选择性地永久钝化。聚苯醚的沉积在低过电势下抑制了针孔电流，但在大过电势下残余法拉第电流变得可见。残余电流归因于电极和部分穿透单层的分子之间的电子隧道效应。
An organized monolayer of octadecanethiol on a gold electrode strongly inhibits faradaic reactions except at pinholes in themonolayer. For simple outer-sphere redox couples, the monolayer-coated elec-trode behaves like a microelectrode array, with pinholes acting as the microelectrodes. The average size and separation of the pinholes can be estimated by fitting the experimental cyclic voltammograms with simulated voltammograms for a microarray electrode. The pinholes are selectively and permanently passivated by electrochemical polymerization of phenol in dilute sulfuric acid. The deposition of poly-(phenylene oxide) suppresses the pinhole currents at low overpotential, but residual faradaic currents become visible at large overpotential. The residual currents are assigned to electron tunneling between the electrode and molecules which partially penetrate the monolayer.