Ce0.8Gd0.2O1.95-based mixed potential type triethylamine sensor utilizing La2NiFeO6 sensing electrode

Abstract

Mixed potential Ce0.8Gd0.2O1.95-based gas sensors utilizing double perovskite type composite oxide La2NiFeO6 – prepared by sol-gel method and sintered at different temperatures – as sensing electrode were fabricated to detect triethylamine (TEA). The influence of the sensing electrode materials with different sintering temperatures on sensing properties of the sensors was mainly studied. Results showed that the sensor utilizing La2NiFeO6 sintered at 1100 °C had the highest response value (−123.2 mV) towards 50 ppm TEA at 490 °C. The greater sensitivity of the sensor was explained by the fact that La2NiFeO6 sintered at 1100 °C had bigger electrochemical active area compared with the other two materials (La2NiFeO6 sintered at 1100 °C/1200 °C), which was confirmed by testing the electric double-layer capacitance (EDLC) of the materials. Besides, the response value of the sensor displayed a linear relationship with the logarithm of TEA concentration, and the slope was −62.2 mV/decade at the range of 0.5–200 ppm TEA. It also displayed good repeatability and selectivity. The fabricated TEA sensor would have good application prospects in the fields spanning from biomedical, chemical detection to seafood safety control.