Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.
Phys Chem Chem Phys. 2012 Nov 7;14(41):14391-9. doi: 10.1039/c2cp42719b.
The first part of this communication studies the electrochemical properties of thin films of poly(3,4-ethylenedioxythiophene) (PEDOT) grown on the three basal plane platinum electrodes via cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy and in situ FTIR spectroelectrochemistry. In the second part of this work the redox reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) at these platinum modified electrodes is investigated via cyclic voltammetry and electrochemical impedance spectroscopy in order to elucidate the effect of some polymer properties on its electrocatalytic behavior, such as the ionic resistance, nature of the doping ion and the structure. First of all, it was found that the ionic resistance of the PEDOT films electrochemically synthesized on platinum electrodes increases in the order Pt(100) < Pt(110) < Pt(111) and the advantages of using single crystal platinum electrodes coated with PEDOT for the IR study of individual mobile species flux and the evolution of charge carriers during the reduction process of p-doped PEDOT were proven. On the other hand, it was found that compact, rigid and low resistance PEDOT films show higher standard charge transfer rates for the DMcT redox reaction than those that have a more porous structure and higher ionic resistance. Finally, PEDOT films doped with alkaline ions are more electrocatalytic for the oxidation process of the protonated form of DMcT.
本通讯的第一部分通过循环伏安法、计时电流法、电化学阻抗谱和原位傅里叶变换红外光谱电化学研究了在三个基面铂电极上生长的聚（3,4-亚乙基二氧噻吩）（PEDOT）薄膜的电化学性能。在本工作的第二部分中，通过循环伏安法和电化学阻抗谱研究了 2,5-二巯基-1,3,4-噻二唑（DMcT）在这些铂修饰电极上的氧化还原反应，以阐明一些聚合物性质对其电催化行为的影响，如离子电阻、掺杂离子的性质和结构。首先，发现电化学合成在铂电极上的 PEDOT 薄膜的离子电阻按 Pt(100) < Pt(110) < Pt(111)的顺序增加，并且证明了使用涂有 PEDOT 的单晶铂电极进行个别移动物种通量的 IR 研究以及在 p 掺杂 PEDOT 的还原过程中载流子演变的优势。另一方面，发现具有致密、刚性和低电阻的 PEDOT 薄膜对 DMcT 氧化还原反应具有更高的标准电荷转移速率，而具有更多孔结构和更高离子电阻的 PEDOT 薄膜则具有更高的标准电荷转移速率。最后，掺杂碱性离子的 PEDOT 薄膜对 DMcT 的质子化形式的氧化过程更具电催化作用。
