電化學
(1. 北京有色金屬研究總院， 北京 100088；
2. 中南大學 礦物工程系， 長沙 410083)
摘 要: 制備了T.ｆ菌修飾碳粉粉末微電極， 應(yīng)用細菌修飾粉末微電極系統(tǒng)研究了Fe2+在T.f菌存在時氧化的電化學反應(yīng)機理， 并測定了相應(yīng)的電極過程動力學參數(shù)。循環(huán)伏安研究表明， Fe2+在T.f菌修飾粉末微電極上的氧化反應(yīng)是一可逆反應(yīng)，且Fe2+濃度在0.22mol/L以下變動時， Fe2+氧化反應(yīng)的可逆程度不變。 對于快速掃描過程， 通過T.ｆ菌修飾粉末微電極上的電流為微盤電流與薄層電流之和。電化學動力學研究認為Fe2+在T.f菌修飾粉末微電極上的氧化反應(yīng)受擴散過程影響，穩(wěn)態(tài)極化法測定的極限擴散電流密度為JL=18.5mA/m2，以此計算的電荷擴散系數(shù)為6.25×10-6cm2·s-1。
關(guān)鍵字: 細菌浸礦; T.f菌修飾粉末微電極;
電化學機理
QIU Guan-zhou2, RUAN Ren-man1
（1. General Research Institute for Nonferrous Metal,
Beijing 100088, China;
2. Department of Mineral Engineering,
Central South University, Changsha 410083, China）
Abstract: The thiobacillus ferrooxidants modified carbon powder microelectrode is prepared, and using it the electrochemical mechanisms of the Fe2+oxidation are studied and the relatively dynamic parameters are measured. Cyclic voltammetry studies show that the oxidation on of Fe2+ the T.ferrooxidans modified carbon powder microelectrode is a reversibility reaction, and at c(Fe2+)＜ 0.16mol/L, the concentration variation of ferrous concentration can not change the reversibility of oxidation reaction. Under quick scan speed, the current through the T.ferrooxidans modified powder microelectrode include the micro-disc and thin layer current. The electrochemical dynamic studies show that the oxidation reaction of Fe2+ is controlled by diffusion process. By steady potentialdynamic measurement, the unti-diffusion current is 18.5mA/m2 and the charge diffusion coefficient is 6.25×10-6cm2·s-1.
Key words: bio-leaching; T.f modified powder electrode; electrochemical mechanism
