镧取代Dawson型磷钨杂多酸聚吡咯修饰电极的制备及其电化学性能

Preparation of Lanthanum(Ⅲ) Substituted Heptadecatungstodiphosphate-Polypyrrole Film Modified Electrode and Its Electrochemical Property

通过缺位填充法合成了分子式为α２－Ｋ７Ｐ２Ｗ１７Ｏ６１（Ｌａ· ＯＨ２）的镧（Ⅲ）取代十八钨磷酸盐。在玻碳电极（ＧＣ）上，用电化学方法将单取代Ｄａｗｓｏｎ型杂多酸盐α２－Ｋ７Ｐ２Ｗ１７Ｏ６１（Ｌａ·ＯＨ２）的阴离子（Ｐ２Ｗ１７Ｌａ）掺杂到聚吡咯（ＰＰＹ）薄膜中制成Ｐ２Ｗ１７Ｌａ／ＰＰＹ／ＧＣ化学修饰电极，既保持该杂多酸的电化学活性和电催化性能，又具有良好的稳定性和灵敏度。研究表明， ０． ５０ ｍｏｌ／Ｌ ＨＣＩ溶液中，聚吡咯薄膜中 Ｐ２Ｗ１７Ｌａ的第一对氧化还原峰对 ＮＯ２的电还原具有良好的催化活性，其催化电流与 ＮＯ２浓度在 ６．０ × １０－５－ １．０ × １０－２ｍｏｌ／Ｌ范围内呈线性关系。

The heptadecatungrtodiphosphate substituted by La(Ⅲ). with the formula α2-K7P2W17O61 (La. OH2) (P2W17La) was prepared by vacant refilling method. The anion of single substituted Dawson-type tungstophosphate salt was doped into the polypyrrole (PPY) film on a glassy carbon electrode (GC) by electrochemical mehtod to prepare the chemically modified electrode (P2W17 La/PPY/GC). It maintains not only the electrochemical activity and electrocatalytic property of P2W17La, but also has good stability and sensitivity. In 0. 50 mol/L HCI solution, the first cathodic peak of P2W17La doping in polypyrrole film can catalyze well the electroreduction of nitrite. The catalytic current was proportional to the concentration of nitrite between 6. 0 ×10-5 and 1 .0 × 10-2 mol/L.