Zinc ferrite (ZnFe₂O₄) for pollutant gas detection

If the pollutants are successfully identified, the air pollution can be addressed. The extraordinary qualities of spinel ferrites can be used for this purpose. The goal of the current work was to create spinel ferrite and evaluate its optical and structural characteristics. This study investigates the use of ZnFe2O₄ nanoparticles (NPs) generated by the precipitation process for static gas sensing applications. Thick films of ZnFe₂O₄ were fabricated utilizing an economical screen-printing method. We examined these films utilizing field effect scanning electron microscopy (FESEM), energy dispersive x-ray analysis (EDAX), x-ray diffraction (XRD), ultra-violet visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Raman analysis to assess their shape, composition, crystalline structure, optical characteristics. The electrical and gas sensing characteristics of the ZnFe₂O₄ films were examined utilizing a half-bridge circuit. The electrical properties, including resistivity, temperature coefficient of resistance (TCR), and activation energy, were evaluated. The resistivity and TCR were measured at 10.4267.8 Ω.m and −0.00191 °C-1, respectively, signifying the material's semiconducting characteristics. The films were evaluated for their gas sensing capabilities in the presence of oxidizing and reducing gases, such as liquefied petroleum gas (LPG), ethanol, nitrogen dioxide (NO₂), carbon dioxide (CO₂), and methane (CH₄). The ZnFe₂O₄ films demonstrated the highest sensitivity of 87.52% to LPG at temperature of 120°C. The films exhibited a swift response time of 12 s and a recovery duration of 83 s upon exposure to LPG. The results highlight the potential of ZnFe₂O₄ as a viable material for economical and effective LPG gas sensors.