CAJ | 학술논문

连续电位阶跃方法是一种研究氧化还原稳定性的有效方法.本文采用连续电位阶跃方法研究了以对甲苯磺酸钠为掺杂剂的聚吡咯(ppy)膜的电化学氧化还原稳定性,通过计算聚吡咯在阶跃电位下的还原电量(Qred),还原和氧化电量的比值(Qred/Qox)考察聚吡咯在H2SO4、Na2SO4和NaOH溶液中在不同电位下的氧化还原可逆性.结果发现聚吡咯过氧化的发生强烈依赖支持电解质的pH值和阶跃电位.在H2SO4溶液中,过氧化的起始电位为0.8 V,而在Na2SO4溶液中.过氧化的起始电位为0.5V.在NaOH溶液中,过氧化在任何电位均可发生,表明溶液中OH-的存在是过氧化发生的直接原因.
련속전위계약방법시일충연구양화환원은정성적유효방법.본문채용련속전위계약방법연구료이대갑분광산납위참잡제적취필각(ppy)막적전화학양화환원은정성,통과계산취필각재계약전위하적환원전량(Qred),환원화양화전량적비치(Qred/Qox)고찰취필각재H2SO4、Na2SO4화NaOH용액중재불동전위하적양화환원가역성.결과발현취필각과양화적발생강렬의뢰지지전해질적pH치화계약전위.재H2SO4용액중,과양화적기시전위위0.8 V,이재Na2SO4용액중.과양화적기시전위위0.5V.재NaOH용액중,과양화재임하전위균가발생,표명용액중OH-적존재시과양화발생적직접원인.
The recurrent potential pulse(RPP)technique is an altemative and effective technique for redox stability measurement.We investigated the electrochemical redox stability of polypyrrole(ppy)films doped with sodium p-toluenesulfohate by RPP technique in this study.The reduction charge(Qred)and the ratio of reduction and oxidation charges(Qred/Qox)obtained from the switching potentials in aqueous solutions of H2SO4,Na2SO4,and NaOH were calculated to describe the reversibility of ppy at the applied potential windows.We found that the irreversible overoxidation strongly depended on the pH value of the suppoding electrolytes and on the switching potentials.The onset of the overoxidation potential is 0.8 V in H2SO4 solution while it is only 0.5 V in Na2SO4 solution.In NaOH solution.overoxidation occurs at any potential indicating that the existence of OH-ions is directly responsible for overoxidation.