Similar to electrochemical impedance spectroscopy (EIS) where electrochemical processes with different characteristic time constants can be separated, dynamic stress analysis (DSA) allows us to study the dynamics of any particular stress-generating process and link the stress to specific electrochemical and surface phenomena. We have demonstrated the technique by examining the electrocapillarity of both Pt and Au in HClO4 electrolyte.3,4 ς can be obtained from the following equation,
ς = jωYsZe
where Ze is the electrochemical impedance, Ys is the stress admittance (with units of N/(V-m), ω is the angular frequency, and j =√-1. In order to include adsorbate-induced contributions to the surface stress, one considers an equivalent circuit that adequately describes both the double layer and adsorption contributions to the electrochemical impedance. One can then obtain unique stress-charge coefficients that capture both electrocapillarity and anion adsorption as a function of potential. This will be demonstrated using (111)-textured Au cantilever electrodes in both sulfate and perchlorate electrolyte.
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