Highly Sensitive Acetone Sensor Based on LaFeO3 Microspheres Prepared by Facile Hydrothermal Synthesis

This paper describes a gas sensor based on LaFeO 3 nanoparticles for sensitive detection of low-concentration acetone. LaFeO 3 nanoparticles were synthesized via a one-step hydrothermal reaction and subsequent annealing. The sample phases and morphologies were investigated by X-ray diffraction, scanning electron microscopy, and the Brunauer—Emmett—Teller method. The results show that the LaFeO 3 nanoparticles were spherical with a loose porous structure. Gas sensors based on the LaFeO 3 nanoparticles were prepared and their gas sensitivities were determined. In particular, the fabricated sensor based on LaFeO 3 nanoparticles annealed at 600 °C showed an excellent response to acetone at 1–300 ppm, and high stability and selectivity. A response of 4.53 toward acetone gas down to 1 ppm at an operating temperature of 120 °C was obtained. This enhanced gas-sensing performance is attributed to a specific mesoporous structure of high roughness, a large surface area, and surface pores of an appropriate size. These properties enable more favorable conditions were provided for gas reaction.