Fabrication and electrochemical property of La0.8Sr0.2MnO3 and (ZrO2)0.92(Y2O3)0.08 interface for trace alcohols sensor

Abstract

Abstract A mixed potential type alcohols gas sensor based on an yttrium stabilized zirconia (YSZ) electrolyte and an La0.8Sr0.2MnO3 (LSM) sensing electrode was fabricated. The influences of YSZ-LSM interface on sensing performance were studied by multiple methods including X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis and differential scanning calorimetry (TG-DSC) and electrochemical impendence spectroscopy (EIS). The sensor with 1150 °C-sintered interface showed an ultralow detection limit of 50 ppb alcohols (methanol and ethanol) at 500 °C in air. The response voltage was independent of water, CO, CO2 and NOx. The sensor exhibited a reasonable selectivity towards alcohols under the existence of several kinds of volatile organic compounds. Meanwhile, the sensor showed a good repeatability and a suitable long-term stability. Based on the polarization curves and EIS results, a mixed potential mechanism was proposed. These results demonstrate the promising potential of using the LSM-based sensor for human exhale test.