YSZ-based NO2 Mixed Potentiometric Sensor with Three-Dimensional Ordered Porous Structure

This study presents the preparation of a nitrogen dioxide (NO2) gas sensor based on yttrium-stabilized zirconia (YSZ) using a hard-template method and evaporation self-assembly technology. The sensing electrode employed is nickel oxide, and the sensor exhibits an efficient three-phase boundary. The study systematically investigates the effects of changing the three-phase reaction boundary on the gas-sensing performance of the sensor. A three-dimensional (3D) ordered macroporous (3DOM) structure was deposited on a YSZ substrate using the hard template method to obtain an efficient three-phase boundary. At 450 degrees C and 100 ppm NO2, the response value of the sensor with a 3D-ordered porous structure was 38.71 mV, which is 1.91 times the response value observed for the untreated YSZ-based sensor (20.3 mV), and the sensitivity significantly improved. In addition, a sensor with a 3D-ordered structure exhibits good 2 selectivity, and long-term stability. The improvement in the sensitivity of the sensor can be attributed to an increase in the area of the three-phase reaction boundary and an increase in the number of active sites in the electrochemical reaction.