Molecular imprinting Ag-LaFeO3 spheres for highly sensitive acetone gas detection

Abstract In this paper, Sliver doped LaFeO 3 nanocrystalline sphere were prepared by sol-gel and molecular imprinting technique (MIT). The carbon microsphere was used as template to regulate the morphology of Ag-LaFeO 3 , and will be burning off after annealing. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The gas-sensing performance of Ag-LaFeO 3 molecular imprinting spheres (MIT Ag-LaFeO 3 spheres) was compared with that of Ag-LaFeO 3 nanoparticles. The gas sensors fabricated with the MIT Ag-LaFeO 3 spheres samples possess high sensitivity and good selectivity than that of Ag-LaFeO 3 nanoparticles. At the optimal operating temperature of 155 °C, the response of the MIT Ag-LaFeO 3 spheres sensor to 5 ppm acetone is 23.3, which is 16 higher than that of Ag-LaFeO 3 sensor, and the response and recovery times are 55 s and 60 s, respectively. It was found that the MIT Ag-LaFeO 3 spheres exhibited excellent acetone gas-sensing properties.