Electrochimica Acta, Vol.56, No.28, 10683-10687, 2011
Impedance study of the ion-to-electron transduction process for carbon cloth as solid-contact material in potentiometric ion sensors
Carbon cloth was studied as solid-contact material in potentiometric ion sensors by using electrochemical impedance spectroscopy and potentiometry. The ion-to-electron transduction process was studied by electrochemical impedance spectroscopy by using a two-electrode symmetrical cell where a liquid electrolyte was sandwiched between two solid electrodes, including bare glassy carbon (GC), GC/carbon cloth and GC/poly(3,4-ethylenedioxythiophene). Impedance data for different electrode/electrolyte combinations were evaluated and compared. Solid-contact K+-selective electrodes were fabricated by coating the carbon cloth with a conventional plasticized PVC-based K+-selective membrane via drop casting. These K+-sensors showed proper analytical performance and acceptable long-term potential stability (potential drift approximate to 1 mV/day). Solid contact reference electrodes were fabricated in an analogous manner by coating the carbon cloth with a plasticized PVC membrane containing a moderately lipophilic salt. The results indicate that carbon cloth can be used as a solid-contact material in potentiometric ion sensors and pseudo-reference electrodes. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Carbon cloth;Poly(3,4-ethylenedioxythiophene);Solid-contact material;Potentiometric ion sensor;Impedance