Preparation and characterization of La_(1-x) Sr _x FeO_3 materials and their formaldehyde gas-sensing properties

摘要

La_(1-x) Sr _x FeO_3 (x = 0.0-1.0) nanoparticles have been synthesized by a sol-gel method. The samples are characterized by thermogravimetric/differential thermal analysis (TG/DTA), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The La_(1-x) Sr _x FeO_3 (x = 0.0-1.0) materials have been sintered at 650 C. Both the structural properties and phase transitions with increasing strontium content in La_(1-x) Sr _x FeO _3 are presented by analysis of XRD data. Formaldehyde gas-sensing properties of La_(1-x) Sr _x FeO_3 have been investigated. The experimental results show that the optimum operating temperatures of La_(1-x) Sr _x FeO_3 varies with Sr content of x. Among all the samples, La_(0.7)Sr_(0.3)FeO _3 shows a maximum response to formaldehyde. Finally, the formaldehyde gas-sensing mechanism has been presented.