Fe^(2+)在T.f菌修饰粉末微电极表面氧化的电化学

Electrochemistry on oxidation of Fe^(2+) on thiobacillus ferrooxidants modified powder microelectrode

制备了T .f菌修饰碳粉粉末微电极 ,应用细菌修饰粉末微电极系统研究了Fe2 + 在T .f菌存在时氧化的电化学反应机理 ,并测定了相应的电极过程动力学参数。循环伏安研究表明 ,Fe2 + 在T .f菌修饰粉末微电极上的氧化反应是一可逆反应 ,且Fe2 + 浓度在 0 .2 2mol/L以下变动时 ,Fe2 + 氧化反应的可逆程度不变。对于快速扫描过程 ,通过T .f菌修饰粉末微电极上的电流为微盘电流与薄层电流之和。电化学动力学研究认为Fe2 + 在T .f菌修饰粉末微电极上的氧化反应受扩散过程影响 ,稳态极化法测定的极限扩散电流密度为JL=18.5mA/m2 ,以此计算的电荷扩散系数为 6 .2 5× 10 -6cm2 ·s-1。

The thiobacillus ferrooxidants modified carbon powder microelectrode is prepared, and using it the electrochemical mechanisms of the Fe 2+ oxidation are studied and the relatively dynamic parameters are measured. Cyclic voltammetry studies show that the oxidation on of Fe 2+ the T.ferrooxidans modified carbon powder microelectrode is a reversibility reaction, and at c(Fe 2+ )< 0.16 mol/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 Fe 2+ is controlled by diffusion process. By steady potentialdynamic measurement, the unti-diffusion current is 18.5 mA/m 2 and the charge diffusion coefficient is 6.25×10 -6 cm 2·s -1 .