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.