| The article was aimed at NO2sensing in vehicle exhaust using YSZ-basedmixed-potential NO2sensor. The sensing performance was improved by designing thethree-phase boundary, which made it a highly sensitive NO2sensor. The researchincluded three aspects:First, to fabricate excellent sensor, the high quality YSZ substrate should befabricated. Therefore, the tape-casting used for fabricating YSZ substrate wasdiscussed, and the best tape-casting process parameter was obtained, which thecontent of binder should be7.5%and the substrate should be kept in400℃and600℃for hours during the sintering process.Secondly, to improve the sensitivity, the porous three-phase was designed,therefore, the double tape-casting and pore-forming was combined. The porosity ofthe substrates increased with doping content (0%,5%,10%and15%), and theresponse to NO2also increased with the doping content. Then, to verify therelationship between the porosity and the response, the polystyrene template was used,the polystyrene was first deposited on the YSZ and the YSZ precursor was theninfused the interspace, and the porosity three-phase boundary was obtained aftersintering. The NO2sensing performance showed that the response also increasedwith the porosity of the surface, which give a conclusion that the porosity of thethree-phase boundary give rise to the sensing response.Finally, the article discussed the principle of NO2sensing withmixed-potential mechanism from the perspective of electrochemical reaction, and theinference that the mixed-potential mechanism fit for the sensor was verified by thepolarization curves. |
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