A double perovskite LaFe1-xSnxO3 nanocomposite modified by Ag for fast and accurate methanol detection

Abstract Perovskite-based metal oxides are one of the most prospective materials for detection of toxic, harmful and explosive gases, but the low electron mobility and ionic conductivity poses challenges in fast and accurate methanol detection. Thus, in this paper, the Ag doped double perovskite LaFe1-xSnxO3 (Ag-LFSO) nanocomposite was prepared via a sol-gel assisted microwave chemical synthesis, which played the dual roles of fast response and good selectivity to methanol detection. The response of Ag-LFSO sensor to 5 ppm methanol is 51.94 at 99 °C, which is approximately 6 times higher than that of the pure LaFeO3 sensor. Moreover, the significant enhancement of response and selectivity to methanol gas can be explained by the compensate for the position of Sn4+ in place of Fe3+ induced change in the carrier concentration and oxygen adsorption for LaFeO3. In addition, Ag-doping can catalyze surface reactions and introduce electron defects at the surface of materials, thereby effectively improving the electrical conductivity and oxygen adsorption characteristics of LFSO. All the results indicated that the double perovskite Ag-LFSO sensor is an ideal choice for detecting toxic and harmful gases in practical applications.