Determination of the pzc at solid electrodes with a dropping electrolyte electrode

The determination of the pzc at solid electrodes requires indirect approach es based on capacitance measurements or thermodynamic methods, exploiting p hysical changes related to double layer structure, like contact angle, adso rption etc. The proposed approach is based on the measurement of the transi ent charging current flowing, on exposure, at the surface of a solid electr ode. The system consists of a static electrode facing upward; an electrolyt e solution drops onto the electrode surface from a capillary situated above it. Between drops, the electrode surface is dried by a continuous stream o f nitrogen. Potentiostatic conditions are established as soon as the metal electrode is re-wetted and the charging current measured. The pzc is charac terized by the absence of the charging current. (C) 2001 Elsevier Science B .V. All rights reserved.