Development of solid contact micropipette Zn-ion selective electrode for corrosion studies

Abstract

The fabrication of a new, solid contact, micropipette ion-selective electrode suitable for use as potentiometric tip in scanning electrochemical microscopy (SECM) is described. Owing to the low resistance, and long life times, these electrodes can advantageously be used in corrosion studies where the measurement of local zinc ion concentrations evolving in surface reactions can give important information about the nature of the process. Data on the properties of these Zn2+ ion selective microelectrodes, namely life time, resistance and ion activity response, are shown. Preliminary findings using them in SECM imaging of zinc ion concentration profiles from a corroding sample are also given. The improvement of scanning rate achieved by lowering the tip resistance is a major advantage in potentiometric SECM