Novel Solid Electrolyte CO2 Gas Sensors Based on c-Axis-Oriented Y-doped La9.66Si5.3B0.7O26.14.

Nowadays monitoring and recording CO2 gas becomes more and more important in various areas, leading to an increasing demand for developing high-sensitive CO2 sensors. In this study, a novel potentiometric CO2 gas sensor is designed based on a new solid electrolyte of Y-doped La9.66Si5.3B0.7O26.14 (Y-LSBO), coating with Li2CeO3-Au-Li2CO3 composite as sensing electrode and Pt as reference electrode. With optimized composition of sensing electrode, the electromotive force (EMF) varies linearly with the logarithm of CO2 concentration in the range of 400-4000 ppm, exhibiting an excellent Nernstian response to CO2 gas in both dry and humid atmospheres. The fabricated CO2 sensor can be well operated at 400 masculineC in dry atmosphere and 450 masculineC in humid atmosphere. Based on the results, we have proposed that the good CO2 sensing performance may be associated with the Li2CeO3 acting a role of "ionic bridge" between O2- conductor (Y-LSBO) and Li+ conductor (Li2CO3). This study not only show the promising potential of Y-LSBO solid electrolyte utilized in the field of gas sensors, but also enrich the research of solid electrolyte-based potentiometric CO2 gas sensors.