Electrochemical Analysis of 0.1M KOH Electrolyte with RuO₂ Working Electrode*

The electrochemical properties of ruthenium dioxide (RuO₂) in a 0.1M KOH electrolyte were investigated using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) techniques. This research aims to contribute to the understanding of RuO₂’s electrochemical behavior in alkaline environments by characterizing the electrode’s impedance response and extracting electrochemical parameters. In this work, EIS measurements were performed using a three-electrode system comprising an RuO₂ working electrode, a platinum counter electrode, and an Ag/AgCl reference electrode. The study primarily focused on evaluating the solution resistance (R_s), charge transfer resistance (R_ct), and double-layer capacitance (Cdl ) of the RuO₂ electrode. The EIS measurements were carried out using a potentiostat, and the resulting data were analyzed over a wide frequency range. From the Nyquist plots, distinct semicircles were observed, indicating the presence of both resistive and capacitive elements within the system. Using curve fitting techniques, R_s and R_ct were accurately quantified, while Cdl was calculated based on the frequency-dependent impedance behavior. These parameters were then used to construct and simulate a Randles equivalent circuit model, consisting of R_s and a parallel combination of R_ct and Cdl. The simulation provided a theoretical framework for interpreting the EIS data, allowing for a comparison between the experimental and simulated impedance spectra. The close agreement between the simulated and experimental data validated the extracted electrochemical parameters and confirmed the suitability of the Randles circuit model for representing the RuO₂ electrode in our 0.1M KOH electrolyte.  In this work, we present our Electrochemical Impedance Spectroscopy measurements and the results of our simulations.