Electrochimica Acta 47 (2002) 3383-3387 pre-print.pdf (131.25 kB)
AC impedance characteristics of solid-state planar electrochemical carbon monoxide sensors with Nafion ® as solid polymer electrolyte
journal contribution
posted on 2013-01-14, 14:20 authored by Roger J. Mortimer, Alison BeechThe AC impedance characteristics of planar solid-state electrochemical carbon monoxide (CO) sensors with Nafion® as the solid polymer electrolyte are reported. For a re-cast Nafion® sensor design, Nyquist plots indicated very high impedances (107–108 Ω), which slightly decreased with an increase in the working electrode surface area (0.25–0.50 cm2). Only one enlarged semi-circle was observed, relating to an equivalent circuit with a geometrical capacitance (Cg) in parallel with a bulk resistance (Rb). In contrast, a sensor design using a commercial membrane produced a system with a much lower impedance (<103 Ω), with Nyquist plots showing a flattened semi-circle at high frequencies (due to Cg and Rb in parallel), followed by the start of a large semi-circle (due to the double-layer capacitance, Cdl, in parallel with the charge-transfer resistance, Rct) over a lower frequency range. On addition of CO, the second circular arc reduced in size, indicating that the interfacial impedance of the electrochemical system had decreased.
History
School
- Science
Department
- Chemistry
Citation
MORTIMER, R.J. and BEECH, A., 2002. AC impedance characteristics of solid-state planar electrochemical carbon monoxide sensors with Nafion ® as solid polymer electrolyte. Electrochimica Acta, 47 (20), pp. 3383 - 3387Publisher
© Elsevier ScienceVersion
- AM (Accepted Manuscript)
Publication date
2002Notes
This article was published in the journal Electrochimica Acta [© Elsever Science]. The definitive version is available at: http://dx.doi.org/10.1016/S0013-4686(02)00275-XISSN
0013-4686Publisher version
Language
- en