Speaker
Description
Volatile organic compounds (VOCs), especially benzene, toluene, ethylbenzene, and xylene isomers (BTEX) are hazardous air pollutants that pose significant risks to human health and the environment, necessitating the development of highly sensitive and selective gas-sensing materials. In this study, Co3O4 and Fe2O3 semiconducting metal oxides (SMO) were synthesized via a microwave-assisted hydrothermal method followed by annealing, and mechanically mixed at weight ratios of 25, 50, and 75% to form Co3O4/Fe2O3 composite. X-ray powder diffraction patterns confirmed the coexistence of cubic spinel Co3O4 and rhombohedral α-Fe₂O3 phases, indicating successful heterostructure formation. Notably, the crystallite size was found to increase with increasing Fe2O3 content (20-23 nm). UV–Vis diffuse reflectance spectra revealed strong absorption at longer wavelengths, leading to reduced reflectance of pure Co3O4. The incorporation of Fe2O3 led to a gradual increase in reflectance, reflecting changes in the electronic structure and optical response of the composites. The optical band gaps were estimated from Tauc plots and found to increase from 1.35 to 2.07eV as Fe2O3 content in the composite increased. The Co3O4/Fe2O3 composites exhibited superior sensing performance for BTEX compared to individual SMOs. The improved performance was associated with the formation of Co3O4/Fe2O3 heterojunctions, promoting the efficient charge separation and transport at the interface, thereby enhancing surface reaction kinetics with VOC molecules and improving sensor response.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |