自組裝單層鈷紫質修飾金電極的製備及電催化2-硫氫乙醇氧化反應研究

本論文製備鈷紫質修飾金電極，並應用於在水溶液條件下電催化氧化2-硫氫乙醇(2-ME)。水溶性的鈷紫質經由4-巰基吡啶將其修飾在金電極表面，此修飾金電極在0.1M NaOH溶液電催化氧化2-硫氫乙醇具有良好的催化活性，我們利用循環伏安法、紫外光-可見光光譜及旋轉盤電極方法探討修飾金電極電化學行為及其穩定性，求出修飾電極表面上2-硫氫乙醇的氧化之異相速率常數及擴散係數。在生物系統及工業上，硫醇的偵測受到廣泛地研究。我們以製備的修飾電極來偵測2-硫氫乙醇。與裸金電極比較，循環伏安法結果顯示其修飾的薄膜能促進電子轉移、只需較低過電位且能增進2-硫氫乙醇氧化電化學行為。此修飾電極製備簡單、快速且可穩定地電催化氧化2-硫氫乙醇。

關鍵字

鈷紫質；修飾電極；電催化； 2-硫氫乙醇

並列摘要

We prepared a cobalt porphyrin-modified electrode, showing characteristics of electrocatalytic oxidation of 2-mercaptoethanol in aqueous solution.The water-soluble cobalt(III) porphyrin was modified onto gold disk surface through 4-mercaptopyridine as a bridge. The modified electrode showed excellent catalytic activity for the 2-mercaptoethanol oxidation in 0.1M NaOH solution. The electrochemical behavior and stability of the modified electrode were investigated using cyclic voltammetry, UV-Vis and rotating disk electrode methods. The heterogeneous rate constant for the oxidation of 2-mercaptoethanol at the surface of the modified electrode and the diffusion coefficient of 2-mercaptoethanol were determined. Detection of thiols has been an important research subject in the biological and industrial world. The obtained modified electrode in this work was used for detection 2-mercaptoethanol in alkaline solutions. Cyclic votammetric results showed that the modified thin fim can facilitate electron transfer, lower the overpotential required and improve electrochemical behavior of 2-mercaptoethanol oxidation, as compared to the bare gold electrode. The way for the assembly of electrodes was easy, fast and highly stable with enhanced performances toward the electrocatalytic oxidation of 2-mercaptoethanol.