Meteor-hammer-like LaFeO3-SnO2 p-n heterostructures for enhanced ethylene glycol sensing at low temperatures

Given the potential risks of metabolic toxicity and organ damage associated with ethylene glycol vapor exposure, the implementation of effective monitoring is essential. In this study, LaFeO 3 -SnO 2 composites with varying mass ratios were synthesized via a hydrothermal-water bath method and subsequently evaluated for ethylene glycol sensing properties. Experimental results indicate that the LaFeO 3 :SnO 2 composite with a mass ratio of 1:2 shows the best sensing performance toward ethylene glycol among all samples. At 145 °C, it achieves a response of 89.522–100 ppm ethylene glycol, which is 435.4 % and 3137.7 % higher than the responses of pure SnO 2 and LaFeO 3 , respectively. Moreover, the operating temperature is 90 °C lower than that of pure LaFeO 3 . Meanwhile, the sensor exhibited great selectivity, repeatability and long-term stability. The improved performance could be attributed to the unique morphology of the LaFeO 3 -SnO 2 composite and the formation of a p-n heterojunction, which facilitated enhanced charge transfer and provided more active sites for ethylene glycol adsorption. Furthermore, density functional theory (DFT) calculations were performed to theoretically confirm the enhancing effect of the heterojunction on the sensing performance. This work is expected to provide new insights and serve as a valuable reference for the application of LaFeO 3 -SnO 2 gas sensors in the detection of ethylene glycol.