磷钼钨杂多酸-L-半胱氨酸自组装膜电极的电化学性质

Electrochemical Properties of L-cysteine Self-assembled Monolayers Modified Gold Electrode of Phosphomolytungstenbdic Anions

磷钼钨杂多阴离子通过分子间静电作用吸附在Ｌ－半胱氨酸自组装单分子膜修饰金电极表面．制备了磷钼钨杂多酸－Ｌ－半胱氨酸自组装超分子膜电极，探讨了成膜条件，采用循环伏安（ＣＶ）、计时库仑（ＣＣ）、水平衰减全反射傅立叶变换红外光谱（ＡＴＲ－ＦＴＩＲ）表征了膜的组成及电化学性质．实验发现，该膜电极在１．０ ｍｏｌ．Ｌ～（－１）Ｈ２ＳＯ４溶液中，于０．８～－０．２Ｖ（ｖｓ ＳＣＥ）间ＣＶ扫描出现３对稳定、可逆的氧化还原峰，计时库仑法计算了薄膜内的电子传递系数Ｄ为２．６４×１０～（－７）ｃｍ～２·ｓ～（－１）。

Phosphomolytungstenbdic anions were adsorbed by electrostatic attraction gold electrode on modified L-cysteine self-assembled monolayers. The formation of the film was studied. Experiments showed that acidic medium was benefit to the adsorption of phosphomolytungstenbdic anions. The adsorbing quantity Gamma (0) is 2.57 x 10(-10) mol . cm(-2), which means a single layer on the surface. Cyclic voltammetry, chronocoulmetry, FTIR and SEM were used for the characterization and electrochemical properties of the films. Three stable and reversible redox couples were observed in 1.0 mol . L-1 H2SO4 in the range of 0.8 similar to -0.2 V, which could be attributed to three electrochemical processes of phosphomolytungstenbdic anions. Charge transfer coefficient is 2.64 x 10(-7) cm(2) . s(-1) by chronocoulmetry. Redox properties were also described.