Enhanced isopropanol vapor detection using Ag nanoparticle-decorated SmFeO3 microspheres

In recent years, respiratory gas analysis has gained considerable attention for the early detection of lung cancer. This paper presents the preparation of gas sensors based on SmFeO 3 porous microspheres using a one-step hydrothermal method. Ag nanoparticles were uniformly loaded onto the surface of SmFeO 3 microspheres through impregnation and annealing strategies. The materials were systematically characterized using techniques such as X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible-near-infrared absorption spectroscopy (UV–VIS-NIR). The gas sensing tests indicated that the 4 % Ag-loaded SmFeO 3 sensor demonstrated the highest response to isopropanol (22.59 at 15 ppm) under operating conditions of 30 % relative humidity (RH) and 225 °C, which is twice that of the pure SmFeO 3 sensor. Moreover, the sensor exhibited excellent selectivity toward isopropanol gas. Ultimately, this paper explores the sensitization mechanism of the Ag-loaded SmFeO 3 sensor, providing technical support for its potential application in the early detection of lung cancer.