Time: 11:40 a.m.
Place: Materials Day 2013, Ruhr-Universität Bochum, Bochum, Germany
Aliaksandr Bandarenka, Ruhr-Universität Bochum, Bochum, Germany
An approach for in-depth characterisation of complex electrode / electrolyte interfaces based on localised impedance measurements is described in-detail. The local ac probing of the interface is performed at different frequencies using micro-electrodes (tips) of scanning electrochemical microscopes (SECM) resulting in dependences of the localised impedance spectra on spatial coordinates. Subsequent fitting of these spectra to physical models visualise the local distribution of important parameters describing the electrochemical interface, such as the electric double layer capacitance and the charge transfer resistance. It is demonstrated that the approach holds promise for the electrochemical surface science, particularly for better understanding of the corrosion processes taking place at metal surfaces in aggressive (particularly, aqueous) electrolytes.