Platinum Metals Rev., 1989, 33, (3), 127
New Sensor for Carbon Dioxide
None of the traditional methods of determining carbon dioxide in atmospheres is particularly applicable to development in cheap, portable sensors. However, a recent paper describes an amperometric sensor which offers these desirable features. Based upon a porous electrode in a three-electrode cell, the electrolyte consists of a copper diamine complex in aqueous potassium chloride (J. Evans, D. Pletcher, P. R. G. Warburton and T. K. Gibbs, Anal. Chem., 1989, 61, (6), 577).
The working and counter electrodes consist of porous polytetrafluoroethene disks spray coated with a platinum layer. The cathode is held at a constant potential; when the solution is contacted by a carbon dioxide-containing atmosphere its pH decreases, this results in the formation of Cu2+, and a current which is strongly dependent on carbon dioxide concentration is observed from the sensor.