Electrochemical and geometrical characterization of iridium oxide electrodes in stainless steel substrate

MAYORGA MARTÍNEZ, CARMEN, MADRID, ROSSANA E. Y FELICE, CARMELO J.

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Año: 2008 vol. 133 p. 682 - 686

0925-4005

A geometrical and electrochemical characterization of stainless steel electrodes electrodeposited with iridium oxide (IrO2) is presented. There is a dramatic increase in the double layer capacitance (C) and an important decrease in the charge transfer resistance (Rct) after electrodeposition, causing also a significant two orders of magnitude reduction of the electrode–electrolyte interface impedance (EEIZ). These phenomena may be explained by the fine-grained iridium oxide, which has a high grain boundary density and which increases the actual electrodic area. An RC model is presented, which would explain the electrical behaviour of the system.