Solid redox polymer electrolyte-based amperometric sensors for the direct monitoring of ozone in gas phase

The response of solid redox polymer electrolytes of the type polyethylene oxide (PEO)/XI/I2 (X: Li, Rb) towards O3 in gas phase is reported for the first time. The proposed approach is based on the current recorded at a redox polymer electrolyte-modified two-gold-surface electrode assembly poised at +300 mV. Ozone reacts with the iodide species in the bulk electrolyte producing triiodides. This results in the increase of the diffusion rate of I3- to the cathode where I3- are reduced to iodides, giving thus rise to the production of a faradic response. Various experimental parameters were optimized and the best results were obtained for the PEO/RbI/I2 redox polymer, which is successfully used for the on-line monitoring of O3 in synthetic air samples in ambient conditions.