Fe2O3-Co3O4 nanocomposite gas sensor for ethanol sensing studies

Abstract

This study focused on pristine Fe₂O₃, pristine Co₃O₄, and Fe₂O₃-Co₃O₄ composite using the Pechini sol-gel method for ethanol gas sensing applications. Advanced characterization techniques were used to analyze the phase, morphology, and composition of the synthesized materials. Gas sensors were then fabricated and used for ethanol gas sensing at different temperatures. The results indicated that Fe₂O₃-Co₃O₄ composite gas sensor crystallized at 600°C, had higher response compared to both pristine Fe₂O₃ and pristine Co₃O₄ gas sensors. The composite sensor manifested a high response of 26.2 to 100 ppm ethanol at 250°C, while maximum responses of pristine Co₃O₄ gas sensor was only 4.4 at 200°C and that of pristine Fe₂O₃ sensor was 11.4 at 300°C. The boosted sensing performance of the composite sensor was related to the formation of p-n heterojunctions between Co₃O₄ and Fe₂O₃ in composite sensor, the formation of dangling bonds at interfaces, and high intrinsic ethanol sensing properties of Fe₂O₃.