Structure-Dependent CO₂ Gas Sensitivity of La₂O₂CO₃ Thin Films

Abstract

Rare earth oxycarbonates are potential candidate materials for constructing simple and low-cost chemiresistive sensors for monitoring carbon dioxide (CO 2 ) gas in the living and working environment for personal comfort and health reasons. Also, measurement of CO 2 concentrations is needed in many industrial processes. Specifically, sol-gel made nanoparticles of Nd and La oxycarbonates have been studied previously as novel CO 2 gas sensor materials. In this paper, pulsed laser deposition of La oxycarbonate (La 2 O 2 CO 3 ) thin films was studied and structural properties of obtained thin films were characterized. Also, CO 2 gas sensing ability of synthesized films was evaluated. The films deposited under CO 2 partial pressure in various conditions were all Raman amorphous. In situ or ex situ annealing procedure at high CO 2 partial pressure was needed for obtaining crystalline La 2 O 2 CO 3 films, whereby hexagonal and monoclinic polymorphs were obtained in ex situ and in situ processes, respectively. Sensor structure, made using in situ process, was sensitive to CO 2 gas and showed relatively fast response and recovery characteristics.

Influence of Lanthanum Oxycarbonate Deposition on Carbon Dioxide Detection

“…Various studies have been carried out on this type of material, such as the performance investigation under CO2 [10], the synthesis process on morphology [10,11] or the kinetics of carbonation and decarbonation between La2O3-La2O2CO3 under CO2 [13]. Other authors such as Kodu et al [14] and Suzuki et al [15] have studied this chemoresistive material for the CO2 sensing. The first author demonstrated the importance of the annealing film on crystalline type oxycarbonate films.…”

Operando Investigations of Rare-Earth Oxycarbonate CO2 Sensors

“…Rare-earth oxycarbonates Ln2O2CO3 (Ln = rare-earth element) have been proposed as promising chemoresistive materials for CO2 sensors [1][2][3][4][5]. The already published results indicate monoclinic La2O2CO3 as the most suitable material for CO2 sensors among this family of materials.…”

P1GS.12 - Crystal Structure and CO2 Sensing Properties of Rare-earth oxycarbonates

“…Obtaining low cost, simple and good performaning chemoresistive CO 2 gas sensors has the potential to be a game changer. Rareearth oxycarbonates have been proposed as promising chemoresistive materials for CO 2 sensors [1][2][3][4][5]. The already published results indicate monoclinic La 2 O 2 CO 3 as the most suitable for material for CO 2 sensors.…”