Journal of Electroanalytical Chemistry ( IF 4.1 ) Pub Date : 2021-08-29 , DOI: 10.1016/j.jelechem.2021.115655 Tamás Pajkossy 1 , Maximilian Urs Ceblin 1 , Gábor Mészáros 1
The use of dynamic electrochemical impedance spectroscopy, dEIS is shown in the context of diffusion-controlled electrode reactions. By this method, a number of audio-frequency impedance spectra were measured on a gold electrode in an aqueous solution of K4[Fe(CN)6] while taking cyclic voltammograms (the CVs were taken with 50–200 mV/s scan-rate; the distance of potentials of impedance spectra was 16 mV). The Faradaic impedance elements were determined from the spectra, from them charge transfer rate coefficients were calculated; it was found to be 0.11 cm/s at the formal potential. This set of measurements demonstrates the main advantage of dEIS over the traditional steady state impedance measurements: dEIS characterization of an electrochemical system can be performed in seconds rather than minutes which makes possible to use freshly prepared (e.g., annealed) electrodes with reduced risk of contamination or modification of their surfaces.
中文翻译:
用于测量金上亚铁/铁氰化物氧化还原对的电荷转移率的动态电化学阻抗谱
动态电化学阻抗谱的使用,dEIS 显示在扩散控制电极反应的背景下。通过这种方法,在 K 4 [Fe(CN) 6水溶液中的金电极上测量了许多音频阻抗谱。] 同时拍摄循环伏安图(CV 以 50–200 mV/s 扫描速率拍摄;阻抗谱的电位距离为 16 mV)。法拉第阻抗元素由光谱确定,由此计算电荷转移率系数;发现在正式电位下为 0.11 cm/s。这组测量证明了 dEIS 相对于传统稳态阻抗测量的主要优势:电化学系统的 dEIS 表征可以在几秒钟而不是几分钟内完成,这使得使用新鲜制备(例如退火)的电极成为可能,降低污染风险或修改它们的表面。