Macroporous Perovskite-Structured LaFeO3 Microspheres and Their Highly Sensitive and Selective Sensing Properties to Alcohols Gas

Alcohols detection is essential for the health of chemical and food production personnel. Metal oxide semiconductor (MOS) gas sensors are widely used, however, sensitive and selectivity of traditional MOS gas sensor is still a bottleneck issue. Recently, ABO ₃ perovskite-type MOS has attracted much attention due to its abundant and controllable physicochemical properties. In this article, macroporous perovskite-type LaFeO ₃ (LFO) microspheres were prepared by simple one step hydrothermal process. The gas sensing test results show that the LFO gas sensor is highly sensitive and selective to alcohols, especially methanol. For 100 ppm methanol, the response value can reach 120 at 215 °C. The excellent gas sensing properties are attributed to the macroporous characteristics (>100 nm), which facilitates the diffusion of methanol molecules inside the nanospheres, enhancing the contact between the gas molecules and the material and improving the gas sensing performance. In addition, the adsorption characteristics and electron exchange processes of eight gases on the material surface were investigated based on first principles analysis. The results show that the hydroxyl group is the main contributor to the stable adsorption of alcohols gas on the material surface. The perovskite-type LFO is a very promising sensitive material for alcohols detection.