Improved potentiometric SECM imaging of galvanic corrosion reactions

The galvanic corrosion of Zn-Cu systems has been monitored in situ using scanning electrochemical microscopy in the potentiometric mode. Here, the initial studies performed using double-barrel microelectrodes for the simultaneous detection of local pH and Zn ion concentration changes in single lines scans, have been extended to the obtention of 2-D maps of Cu2+ and Zn2+ ions. The construction and calibration of a novel Cu2+ ion selective microelectrode is reported. New scanning algorithms and data evaluation tools have been explored for faster acquisition rates than those limited by the time constants associated to potentiometric response.