Implementation of Second-Generation Fourier Transform Electrochemical Impedance Spectroscopy with Commercial Potentiostat and Application to Time-Resolved Electrochemical Impedance Spectroscopy.

ABSTRACT

We report the implementation of second-generation Fourier transform electrochemical impedance spectroscopy (2G FT-EIS) with commercial potentiostat. Although 2G FT-EIS based on chronoamperometry has several advantages of short measurement time and ability of time-resolved EIS, a special home-built electrochemical system is essential, which has been an obstacle to the wide application of 2G FT-EIS. Current commercial potentiostat and software, however, has sufficient power thanks to recent state-of-the art electronics and software industry. 2G FT-EIS requires two signals of time versus voltage and time versus current from chronoamperometry with a high sampling rate. In this work, auxiliary input of a commercial potentiostat was used to record voltage signal concomitant with typical chronoamperometry that consisted of time versus current. This simple approach enables the 2G EIS without expensive frequency response analyzer (FRA) and the complex home-built instrument. EISs with various charge transfer kinetics were investigated by the formation of a self-assembled monolayer (SAM) on Au with different chain lengths. More to the point, in situ time-resolved EISs during the SAM were obtained, demonstrating the ability of a commercial potentiostat for time-resolved EIS.