| To accurately monitor and control NOx,research on high performance,miniaturization and low cost sensors are particularly important.Solid electrolyte type NO2 sensors are research hotspots due to their high sensitivity,rapid response speed and good selectivity.The sensitivity of sensors are mainly affected by the composition of the sensitive electrode(SE)and construction of three-phase boundary(TPB).Anion-doped La0.75Sr0.25CrO3-x-δAx(LSCAx,A=F-,Cl-,Br-)sensitive materials were prepared by impregnation method and applied to impedencemetric-type NO2 sensors.Compared with Cl" and Br-,F" doping improves the adsorption of NO2 on SE,promotes the electrochemical reaction at TPB,and significantly improves the sensitivity of the sensor.The sensor based on LSCF0.05-SE has largest Θ response and highest sensitivity.In addition,the sensor has good anti-interference ability to CH4,CO2,NH3,H2 and NO.The mixed conductor porous layer was prepared by doping NiO as the electronic conductor into oxygen ion conductor yttria-stabilized zirconia(YSZ).Adding the proper amount of NiO into the YSZ porous layer does not change the structure of the porous layer.In addition to the oxygen ion conduction performance of TPBs,the electronic transfer channel is increased,thereby increasing the response performance of the sensor.Compared with the sensor of the pure oxygen ion conductor YSZ,the doping of 50 wt%NiO can make the response of the sensor more stable,and can significantly improve the response value and sensitivity.The NiO/Ce0.8Gd0.2O1.9(CGO)-SE was prepared in the porous layer of mixed conductor by impregnation method and applied to the impedance NO2 sensor.Using Θand Z" as response signals,the sensor has faster response recovery rate and more stable response.Compared with NiO-SE,the sensitivity of sensor based on NiO+10%CGO-SE is nearly two times higher.The sensor shows good response and recovery performance in the temperature range of 450～550 ℃,and the sensor has good anti-interference ability to CH4,CO2,NH3,H2 and NO.Figure 39;Table 4;Reference 72... |
