Novel Solid Electrolyte CO2 Gas Sensors Based on c-Axis-Oriented Y-Doped Lasibo

Abstract

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), coated with Li2CeO3-Au-Li2CO3 composite as sensing electrode and Pt as reference electrode. With optimized composition of sensing electrode, the EMF varies linearly with the logarithm of CO2 concentration in the range of 400-4000 ppm, exhibits an excellent Nernstian response to CO2 gas in both dry and humid atmospheres. The functionalization of optimized Li2CeO3-Au-Li2CO3 composite on Y-LSBO solid electrolyte give rise to the formation of an interfacial layer, serving as an “ionic bridge” between the O2- conductor (Y-LSBO) and the Li+ conductor (Li2CO3). Therefore, the designed sensor device can track CO2 concentration by monitoring EMF change, and exhibits an excellent Nernstian response to CO2 gas both in dry and humid atmospheres. This study provides the possibility of Y-LSBO solid electrolyte as a potentiometic gas sensor to measure CO2 in the environment, demonstrating that Y-LSBO is not only a promising solid electrolyte for oxygen pump and solid oxide fuel cell but also for gas sensor. Figure 1