In Situ Local pH Measurements with Hydrated Iridium Oxide Ring Electrodes in Neutral pH Aqueous Solutions

In electrochemical reactions involving protons or hydroxide ions, local pH in the vicinity of a working electrode dynamically changes. In this study, we introduce the measurements of the local pH in solutions using a rotating ring-disk electrode (RRDE) modified with iridium oxides. Monitoring the potential of the ring electrode (iridium oxides), which was sensitive to pH, we successfully evaluated the dynamic changes in the local pH of the working electrodes.