恒电位组装的硫醇单层膜的电化学性质

采用恒电位组装的方法在金基底上制备了十二硫醇单层膜,用反射傅立叶红外光谱、循环伏安法和电化学阻抗谱对得到的硫醇膜进行了表征.结果表明,恒电位组装1 min即可在金基底上形成没有针孔缺陷的硫醇单层膜.随着恒电位组装时间的增加,硫醇膜上的凹陷点缺陷逐渐减少,致密程度逐渐增加.当恒电位组装时间达到5 min时,得到的硫醇膜与自组装24 h的硫醇膜具有相当的致密度和更少的凹陷点缺陷.

Electrochemical Properties of Thiol Monolayers Prepared by Constant-Potential Assembly

The monolayer of dodecanethiol was prepared on gold surface by constant potential assembly (CPA). The properties of the monolayers were characterized using reflection absorption FT IR, cyclic voltammetry, and electrochemistry impedance spectroscopy. Experimental results show that monolayers free from pin hole defects can be obtained after CPA for 1 min. As the assembling time increases, the number of collapsed site defects decreases and the packing density of the thiol monolayer increases. Compared to the monolayers prepared by self assembly for 24 h, those obtained by CPA for 5 min have almost identical packing density and less collapsed site defects.