Rare-Earth Based Chemoresistive CO2 Sensors

This study demonstrates that depending on the preparation method and the element, both oxycarbonates and oxides of rare earths can show significant gas sensing responses when exposed to CO₂. This is valid for Sm, Gd, Dy, Er, and Yb but not for Ce and Nd. We have synthesized the rare-earth oxycarbonates and the rare-earth oxides by the heat treatments in air of the oxalate hydrate or the acetate hydrate and made evaluations focused on their performance in application conditions.