Sonoelectrochemistry understood via nanosecond voltammetry: Sono-emulsions and the measurement of the potential of zero charge of a solid electrode

"Nanosecond" electrochemistry is used to study acoustically emulsified mixtures of aqueous electrolyte and smaller quantities of heptane. Significant current spikes of microsecond duration are observed under potentiostatic conditions and attributed to the impacting of heptane droplets onto the electrode surface. The polarity of the transients is found to change as the electrode potential varies through the accepted potential of zero charge of the electrode/electrolyte system for both gold and platinum electrodes. A possible explanation is suggested and the implications for a generic approach to the experimental measurements of potentials of zero charge (pzc) of solid electrodes noted.