The effects of sintering temperature of (La0.8Sr0.2)2FeMnO6−δ on the NO2 sensing property for YSZ-based potentiometric sensor

Abstract

In this paper, (La0.8Sr0.2)2FeMnO6−δ (LSFM) oxide powder with double-perovskite structure has been prepared by using Pechini method to fabricate sensitive electrode (SE) for NO2 potentiometric sensors based on yttria-stablized zirconia (YSZ). The sensing electrodes of LSFM sintered at different temperatures (1000, 1100, 1200 and 1300°C) were characterized by X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM). NO2 sensitivity was tested at 550–700°C respectively for the sensors with the sensing electrodes of LSFM. The result demonstrated that the phase composition of LSFM sensing electrode was affected by the sintering temperature. The NO2 sensitivity of the sensor was found to be modulated by the morphology of LSFM sensing electrode. The catalytic activity of the gas-phase decomposition of NO2 was influenced by the microstructures of the LSFM powders sintered at different temperatures. The sensor with 1200°C-sintered LSFM sensing electrode, which had relatively perfect three-dimensional network structure, exhibited the highest NO2 sensitivity. The selectivity to NO2 for the sensor with 1200°C-sintered LSFM sensing electrode is good at 550°C.