Stoichiometric-Induced Cationic Inversion of Cobalt Ferrite for High-Sensitivity Acetone Gas Sensor and Mechanistic Insight

On the ground that acetone is a common flammable and physiologically toxic gas, it is an important task to detect acetone sensitively. Cobalt ferrite exhibits promising characteristics for enhancing gas sensitivity due to their variable polyvalent cations and controllable components, yet lucubrate on the gas sensing capabilities is still inadequate. In this study, a series of cobalt ferrite Co x Fe (3– x ) O 4 ( x = 0.47–0.87) nanoparticles were synthesized for sensitive detection of acetone gas, and the factors impacting the sensing performance were explored. The response magnitude of Co 0.57 Fe 2.43 O 4 to 100 ppm of acetone at 150 °C reaches 348.6, which is often greater than other ferrite materials. The improvement of acetone sensing performance is ascribed to the degree of lattice inversion, enhanced catalytic activity, and surface oxygen vacancy content, allowing for the increase of metal centers for gas adsorption coupled with the most favorable adsorption energy ( E ads = −1.747 kJ/mol). This study has established a comprehensive composition-property-dependent Co x Fe (3– x ) O 4 acetone sensing model, which is of great significance for the sensing applications of bimetallic oxides.