Mixed-potential type triethylamine sensor based on NASICON utilizing SmMO3 (M = Al, Cr, Co) sensing electrodes

The polycrystalline perovskite SmMO3 (M = Al, Cr, Co) sensing electrode was synthesized by the sol-gel method, and the NASICON-based sensors attached with SmMO3 were designed and fabricated for triethylamine (TEA) detection. This study investigated the effects of different M3+ ions in SmMO3 and various calcination temperatures of the sensing material on TEA sensing properties. The results reveal that compared with the other devices, the sensor attached with SmCrO3 sintered at 800 degrees C displays a higher response value (-108.2 mV) towards 100 ppm TEA, and that the sensor even detects 2 ppm TEA with an acceptable value (-6 mV). The sensor utilizing SmCrO3 (800 degrees C) also exhibits pretty swift response and recovery times of 2 and 22 s, respectively, toward 20 ppm TEA. A linear relationship exists between the response values and the logarithm of TEA concentrations, and the sensitivity is -64 mV/decade. At the same time, good repeatability, selectivity, and long-term stability of the sensor are also observed. Furthermore, the sensing mechanism related to the mixed potential model is demonstrated by the polarization curve measurements.