Leveraging the Surface Effect of Dual-Phase Lanthanum Dioxycarbonate to Sense Carbon Dioxide

In this study, fabrication of dual phased La2O2CO3 films using an electrostatic spray technique was investigated and the developed films were used as CO2 gas sensors. Results demonstrated that La2O2CO3 films contained relatively high amounts of hexagonal phase formation when high concentrations of polyvinyl pyrrolidone (PVP) are used. Furthurmore, low concentrations of PVP yielded discontinuous films. The gas sensing results demonstrated that sensing efficiency can be improved by optimizing the concentration of PVP content. The results indicated that the highest response of 18% in the presence of 2000 ppm CO2 was attained by the film having a PVA concentration of 6 wt%. Structural and elemental analysis of La2O2CO3 films were verified using X-ray diffractometry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analyses. This study validates the sensing functionality of dual-phase La2O2CO3 films, which can function at gas concentrations that are as low as 800 ppm and are environmentally friendly.