Development of a high performance ethylene glycol gas sensor using cobalt doped porous ZnFe₂O₄ nanostructures

Porous ZnFe₂O₄ microspheres consisting of interwoven nanosheets doped with different concentrations of cobalt (ZC) with a diameter of approximately 1.5 μm were synthesized by a simple hydrothermal method. The synthesized samples were comprehensively characterized using XRD, FESEM, FTIR, BET, and UV-Vis analyses. The synthesized ZCs were studied to investigate the effect of doping on the gas sensing properties. Interestingly, the prepared ZCs showed enhanced gas sensing performance towards ethylene glycol, with the response value increasing from 107.5 to 119.6 for 500 ppm ethylene glycol compared to the pure ZC sample under the same conditions. The rough surface morphology that creates a high surface area and the appropriate doping effect that enhances the surface chemical oxygen accumulation by creating some new energy levels, provide a fast response (less than 3.6 s) with excellent response, allowing us to perform sensing experiments at concentrations of 20-500 ppm ethylene glycol in a short time. The ZCs-based sensors also showed significant selectivity over ethylene glycol at a low operating temperature of 210 °C through a comparison of the sensing properties with ethanol, acetone, isopropanol, and dimethylamine. The results indicate that the ZC material has special potential for ethylene glycol sensors.