Conductivity dependence of the polarisation impedance spectra of platinum black electrodes in contact with aqueous NaCl solutions

TIRADO, MONICA; GROSSE, CONSTANTINO

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

ELSEVIER SCIENCE B. V.

Lugar: Amsterdam, Holanda ; Año: 2003 vol. 222 p. 293 - 299

0927-7757

The polarization resistance and capacitance of platinum black electrodes in contact with aqueous NaCl solutions was investigated. A series of measurements were made at 259 / 0.1 8C in the 10 Hz to 10 MHz range using a HP 4192A Impedance Analyzer. The measurement cell has flat parallel platinum electrodes 15 mm in diameter, with a continuously variable spacing from 0.5 to 9 mm. They were platinized prior to each measurement. The electrolyte solution conductivities were in the 0.004 / 0.6 S/m range. The data were analyzed using an equivalent circuit consisting in a constant phase element in series with a parallel connection of a resistance and another constant phase element. The characteristic parameters of the model are presented as a function of the electrolyte solution conductivity.