电聚合制备维生素B_(12)修饰电极及其特性研究

Study on the Characteristics of VB_(12) Modified Electrode by Electropolymerization

以玻碳电极为工作电极,电聚合法制备VB12修饰电极,该修饰电极对亚硝酸根离子,亚硫酸根离子和肼均具有催化活性.在pH=2.3的磷酸缓冲底液中,电极对NO2-的催化氧化电位为0.76V(vs.SCE),催化氧化电流与NO2-的浓度在1.6×10-6～4.3×10-4mol.L-1范围内呈线性关系,其线性方程为ip=-24.68+12.36C,相关系数0.9987.应用该电极测定水中的NO2-,稳定性好,灵敏度高.

Preparation of the VB12 modified electrode and its electrochemical characteristics were studied. The results showed that the VB12 after electroactivated is able to electopolymerize on the GC by cyclic voltammetry （CV） in the DMSO solution. Differential pulse voltmmetry （DPV） showed that the VB12 catalyzed the oxidation of NO2 ^- , SO3^2- and NH2NH2. The catalytic peak for NO2 ^- on the modified electrode was observed at 0.76V （ vs. SCE） , but on the unmodified GC which at 1.0V. The catalytic currents increased linearly with the concentration of NO2^ - from 1.6 x 10^-6 to 4.3 x 10^-4 mol. L^-1 with a correlation coefficient of 0. 9987. The VB12 mod- ified electrode showed excellent stability and high sensitivity to determined the NO2 ^- in the rains and lake waters with a recovery of 92% - 107%.