Effects of WO₃ electrode microstructure on NO₂-sensing properties for a potentiometric sensor.

ABSTRACT: Planar potentiometric NO₂ sensors based on 8YSZ (8 mol% Y₂O₃-doped ZrO₂) were prepared with WO₃ sensing electrode material. The various electrode microstructures prepared by different sintering temperatures were characterized by field emission scanning electron microscopy (SEM), and the microstructure influences on the sensors' performances were investigated. The sensor sintered at 800°C, with the most reaction sites, moderate adsorption sites and appropriate electrode thickness, exhibits the highest NO₂ voltage response. While the sensor sintered at 750°C exhibits the lowest NO₂ sensitivity because of the strongest gas-phase catalytic consumption in the WO₃ sensing electrode. Based on the results of SEM characterization and electrochemical impedance spectroscopy tests, the difference in NO₂-sensing performance was attributed to different amounts of electrochemical reaction sites at three-phase boundary, adsorption sites and different degrees of gas-phase catalysis.

SUBMITTER: Yang B 

PROVIDER: S-EPMC6689626 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature