A Solid Electrolyte Impedancemetric NOx Sensor Using Oxide Receptor

Solid-electrolyte impedance-metric NOx sensor devices composed of a lithium ionic solid electrolyte: Li1.5Al0.5Ti1.5(PO4)3 (LATP) as a transducer and a ceramic oxide as a receptor, respectively, have been systematically investigated for the detection of NOx (NO and NO2) in the range 10-200ppm at 400- 500ºC. Responses of the sensors were able to divide component between resistance and capacitance, and it was found that the device was applicable to the selective detection of NO or NO2 concentration in each ingredient. Especially, those using TiO2, SnO2 (n-type semiconductor) and perovskite-type oxide based receptors gave good responses to NO and NO2.