A universal quasi-reference electrode for in situ EC-STM

The use of an activated carbon based quasi-reference electrode for in situ electrochemical scanning tunneling microscopy was found to allow investigations of electrode/electrolyte interfaces under realistic electrochemical reaction conditions. The implementation of purely inert porous carbon electrode materials, both as reference and counter electrode, ensures a stable reference electrode potential over a wide range of temperatures and in different electrolytes, which renders this electrode ‘universal’. Furthermore, the high surface area carbon can reduce and even eliminate contaminations that might be present in the electrolyte. Activated carbon electrodes can therefore generally contribute to more reliable electrochemical measurements when investigating electrochemical reactions under complex experimental conditions, where the use of classical secondary reference electrodes is impossible or impractical. This is often the case when electrochemistry is combined with in situ interface analytics. Keywords: Electrochemical scanning tunneling microscopy, Quasi-reference electrode, Activated carbon