Imaging concentration profiles of redox-active species in open-circuit corrosion processes with the scanning electrochemical microscope

Scanning electrochemical microscopy has been used to detect the redox species involved in a corrosion process at the open-circuit potential. During the immersion of pure iron in a neutral aqueous solution, the potential of the ultra microelectrode (tip) was set to either detect the Fe2+ ions originating from the electrodissolution of iron at the anodic sites on the metal surface, or the depletion of oxygen in the electrolyte in the proximity of the corresponding cathodic sites. (C) 2004 Published by Elsevier B.V.