title: Ionic liquids as electrolytes for the development of a robust amperometric oxygen sensor.
abstract: A simple Clark-type online electrochemical cell design, consisting of a platinum gauze working electrode and incorporating ionic liquids (IL) as electrolytes, has been successfully applied for the amperometric sensing of oxygen. Studying ILs comprising the bis(trifluoromethylsulfonyl)imide anion, the obtained analytical parameters were found to be strongly dependent on the choice of cation. Compared with a conventional Clark cell design based on an aqueous supporting electrolyte, the modified oxygen sensor achieves substantial improvements in performance and stability. A limit of detection for oxygen as low as 0.05 vol %, linearity over an oxygen partial pressure between 0% and 20%, and a steady-state response time of 2 min was demonstrated, with a stable analytical response shown over the examined period of 90 days with no obvious fouling of the electrode surface. Based on the attractive physical attributes of ionic liquids (e.g., thermal stability beyond 150 °C), one can envision intriguing utility in nonstandard conditions and long-term online applications, as well as extension to the determination of other gases, such as methane and nitric oxide.
authors.affiliation: Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Peiling
authors.initials: P
authors.lastname: Lin
authors.forename: Gary A
authors.initials: GA
authors.lastname: Baker
authors.forename: Joseph
authors.initials: J
authors.lastname: Stetter
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Zeng
mesh_terms: D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008697:Methane / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D010100:Oxygen / Q000032:analysis*; D011312:Pressure
chemical_list: D004573:Electrolytes; D052578:Ionic Liquids; D009569:Nitric Oxide; D008697:Methane; D010100:Oxygen