Improvement of the gas sensing response of nanostructured LaCoO3 by the addition of Ag nanoparticles

• DOI: 10.1016/j.snb.2017.02.045
• Publication Date: 2017-02-16T04:37:04Z
• Authors: Carlos R. Michel; Alma H. Martínez-...; Edgar R. López-Mena; Alex Elías-Zuñiga; Nicolás Cayetano-...; Oscar Ceballos-Sa...
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract LaCoO 3 decorated with nanoparticles of noble metals has been proposed as catalyst in Suzuki reactions, automotive catalytic converters and gas sensors. In this work, LaCoO 3 decorated with silver nanoparticles (AgNPs) was prepared by the solution-polymerization method, using polyvinyl alcohol (PVA) as polymerizing agent. For comparative purposes, LaCoO 3 was also synthesized by this method. Calcination at 500 °C produced LaCoO 3 ; however, better crystallinity was obtained at 700 °C. To attach AgNPs to LaCoO 3 , a simple wet impregnation process was used. The microstructure of samples displayed interconnected nanoparticles and extensive porosity. Ag-LaCoO 3 shows AgNPs with average size of 10 nm. Gas sensing characterization performed at 250 °C revealed high reproducibility for detecting CO, CO 2 and excess O 2 (in air). The results obtained from Ag-LaCoO 3 exhibit better stability and the quantitative detection of the test gases. In conclusion, surface decoration of LaCoO 3 with AgNPs resulted in an effective and low-cost approach to improve the gas sensing properties of LaCoO 3. This process can also be used to enhance the gas response of other oxide perovskites.