Electrochemical characterization of self-assembled alkylsiloxane monolayers on indium-tin oxide (ITO) semiconductor electrodes
Electrochemical characterization of self-assembled alkylsiloxane monolayers on indium-tin oxide (ITO) semiconductor electrodes
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DOI：
10.1021/jp004062n
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发表时间：
2001-05-17
影响因子：
3.3
通讯作者：
Tanaka, M
中科院分区：
文献类型：
--
作者：
Hillebrandt, H;Tanaka, M
在氧化铟锡(ITO)电极表面沉积了辛基三甲氧基硅烷(OTMS)自组装单分子膜。接触角测量表明，尽管多晶ITO电极具有固有的表面粗糙度，但功能化表面的疏水性和均一性得到了证明。用循环伏安法和阻抗谱定量分析了OTMS单分子膜的电阻、介电厚度、扩散常数和缺陷面积等电化学性质。研究表明，烷基硅氧烷单分子膜起到了离子在电解液中扩散的阻挡作用。此外，还观察到了界面电荷转移的显著抑制，表明单分子膜对电化学的钝化作用。并用十八烷基三甲氧基硅烷(ODTMS)分析了烷基链长对其电化学性能的影响。这种自组装单分子膜的缺陷面积减少到0.2%。
Self-assembled monolayers (SAMs) of octyltrimethoxysilane (OTMS) were deposited onto indium-tin oxide (ITO) electrode surfaces. Contact angle measurements evidenced the hydrophobicity and homogeneity of the functionalized surface despite the intrinsic surface roughness of the polycrystalline ITO electrodes. The electrochemical properties of the OTMS monolayers were quantitatively analyzed in terms of resistance, dielectric thickness, diffusion constant, and defect area by cyclic voltammetry and impedance spectroscopy. It has been demonstrated that the alkylsiloxane monolayer acts as a diffusion barrier for ions in the electrolyte. Furthermore, a significant suppression of the charge transfer at the interface was observed, demonstrating the passivation effect of the monolayers against electrochemistry. In addition, the effect of alkyl chain length on the electrochemical properties was briefly analyzed by using octadecyltrimethoxysilane (ODTMS). The defect area of this self-assembled monolayer was reduced to 0.2%.