若干电子传递体在聚邻苯二胺膜电极上氧化还原的伏安法研究

Voltammetrric Studies of the Redox Processes of Some Mediators at Poly(o-phenylenediamine )Membrane Electrodes

用伏安法分别在ｐＨｌ．０和ｐＨ７．０的磷酸盐缓冲溶液介质中研究了Ｆｅ￣２＋，Ｉ￣－，以及苯醌和萘醌等物种在聚邻苯二胺（ＰＰＤ）膜电极上的氧化还原行为。结果表明由于ＰＰＤ膜具有选择性通透性能，所述阳离子不能在膜电极上反应，阴离子和中性分子则可反应，而且阴离子的反应速度比裸露基体电极上的大。在ｐＨｌ．０溶液介质中上述氧化还原反应发生在ＰＰＤ膜的电化学惰性区；而在ｐＨ７．０溶液介质中醌的还原延伸到ＰＰＤ膜的电化学活性区，此时膜参与电化学过程，并表现为导电聚合物而不是氧化还原聚合物。

By voltammetry. the redox processes of Fe￣2+,I￣- benzoquinoneand naphthoquinone were studied at poly(-o-phenylenediamine)membrane(PPD)electrodes inpH l.0 and pH 7.0 phosphate buffer respectively. The results showed that PPD membraneexhibited the permselectivity to the ions and molecules,therefore,the cations above-mentionedcan not react at the membrane electrode,whereas the anions and neutral molecules can. Andfurther,the reaction rates of the anions are higher than those at naked electrodes. In pH 1.0solution the redox processes take place in the pontential region where PPD is inertelctrochemically,however,in pH 7.0 solution benzoquinone reduction extends to the potentialregion where PPD is electochemically active,then the PPD participates in the electrochemicalprocesses and manifests itself the conducting polymer more than redox polymer.