September

Picture of the Month - September 2019

Here you see current insights into the research of the LaMa groups. A collection of the former pictures can be found in the Gallery.

Potential-Induced Pitting Corrosion of IrO₂(110)-RuO₂(110)/Ru(0001) Model Electrodes

Recently, sophisticated IrO₂(110) ultrathin films supported on RuO₂(110)/Ru(0001) were prepared and employed as model electrodes for stability studies under Oxygen Evolution Reaction (OER) conditions. In situ synchrotron-based studies (SXRD, XRR) complemented by ex situ techniques (SEM, ToF-SIMS) revealed potential-induced pitting corrosion to be operative: the degradation of the model electrode proceeds rather by disordering of the surface region than by electrochemical dissolution of the IrO₂(110) film. The figure summarizes the changes in the morphology and chemical composition due to potential-induced pitting. FIB-SEM reveals a cylinder-like shape of the pits, while ToF-SIMS indicates the presence of electrochemically formed hydrous RuO₂ within the pits.

This picture was submitted by Tim Weber, group of Prof. Dr. Herbert Over.