Towards improving the robustness of electrochemical gas sensors: Impact of PMMA addition on the sensing of oxygen in an ionic liquid
MetadataShow full item record
The electrochemical reduction of oxygen (O2) has been studied on commercially-available integrated Pt thin-film electrodes (TFEs). Chemically reversible (but electrochemically quasi-reversible) cyclic voltammetry was observed in the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]), showing superior behaviour of TFEs compared to screen-printed electrodes for oxygen sensing. As a step towards the preparation of robust gas sensors, the RTIL was mechanically stabilised on the TFE surface by the addition of poly(methyl methacrylate) (PMMA). At a PMMA concentration in the RTIL of ca. 50% mass, electrolyte flow was not evident. O2 reduction peak currents were found to decrease systematically with increasing PMMA content, reflecting the higher viscosity of the electrolyte medium. Linear calibration graphs were obtained for 0–100% vol. oxygen at all PMMA–RTIL mixtures studied. The sensitivities decreased as [PMMA] increased, but the limits of detection were relatively unchanged. Mechanical stability of the sensors was tested in different orientations (flat, upside down, sideways) with both the neat RTIL and 50% mass electrolyte. Whilst the electrochemical responses were dramatically changed for the neat RTIL, the responses in the PMMA–RTIL mixture were independent of electrode orientation. Additionally, the oxygen response in the PMMA–RTIL mixture was less affected by atmospheric impurities and moisture, compared to the neat RTIL. This suggests that these low-cost miniaturised devices can successfully be used for oxygen sensing applications in field situations, especially where portability is essential.
This open access article is distributed under the Creative Commons license http://creativecommons.org/licenses/by/3.0/
Showing items related by title, author, creator and subject.
Low-cost microarray thin-film electrodes with ionic liquid gel-polymer electrolytes for miniaturised oxygen sensingLee, J.; Silvester, Debbie (2016)A robust, miniaturised electrochemical gas sensor for oxygen (O2) has been constructed using a commercially available Pt microarray thin-film electrode (MATFE) with a gellified electrolyte containing the room temperature ...
Screen-Printed Graphite Electrodes as Low-Cost Devices for Oxygen Gas Detection in Room-Temperature Ionic Liquids.Lee, J.; Hussain, G.; Banks, C.; Silvester, Debbie (2017)Screen-printed graphite electrodes (SPGEs) have been used for the first time as platforms to detect oxygen gas in room-temperature ionic liquids (RTILs). Up until now, carbon-based SPEs have shown inferior behaviour ...
Oxygen reduction voltammetry on platinum macrodisk and screen-printed electrodes in ionic liquids: Reaction of the electrogenerated superoxide species with compounds used in the paste of Pt screen-printed electrodes?Lee, J.; Murugappan, Krishnan; Arrigan, Damien; Silvester, Debbie (2013)Screen-printed electrodes (SPEs) are widely investigated as simple, three-electrode planar surfaces for electrochemical sensing applications, and may be ideal for gas sensing purposes when combined with non-volatile room ...