First results from coupled acousto-ultrasonics and electrochemical noise techniques applied to gas evolving electrodes

This paper presents the first results obtained from the coupling of acoustic emission, ultrasonic testing and electrochemical noise measurements for the real-time monitoring of metal–electrolyte interfacial processes of stochastic nature. In this first paper, this combined approach is applied to gas-evolving electrodes (hydrogen and oxygen) to verify the ability of acoustic–ultrasonic measurements to complement the purely electrochemical information brought by conventional potential and current electrochemical noise measurements. Results have been treated both in the time and frequency domains indicating that acoustic–ultrasonic measurements actually sense the dynamic bubble evolution behaviour. It is hence shown that this new approach is a promising efficient tool that can be potentially extended to the study of other complex multiphase phenomena.