PAn/Pt修饰电极的电色效应及其在滴定分析中的应用

ELECTROCOLORATION EFFECT OF PAn/Pt MODIFIED ELECTRODE AND ITS APPLICATION IN TITRIMETRY

采用恒电位电解聚合的方法制备了聚苯胺修饰电极 (PAn/Pt) ,循环伏安法分析表明 ,该电极在无机酸溶液中是电活性的 ,且随着颜色的变化呈现不同的电位响应 ,应用于滴定分析中具有灵敏度高、不污染溶液等特点 ,是一种有价值的显色指示电极。

The method of potentiostatic electrolytic polymerization was used in the preparation of the PAn/Pt modified electrode. The results of cyclic voltammetric study showed that the modified electrode was electroactive in inorganic acid mediums and that different potential responses were observed accompanied by change in different colors. A more sensitive color change was observed by using this PAn/Pt modified electrode as an indicator electrode in the titration of Fe(Ⅱ) with Ce 4+ and a more sharp end point was obtained as compared with the use of o-phenanthroline-Fe(Ⅱ) complex as inside indicator, which was considered to be a pollution to the titration solution in some cases. It was considered that this PAn/Pt modified electrode with its electrocolor changing effect was more profitable and valuable to be used as an indicator electrode in redox titrimetry.