Detection of propionaldehyde with mixed potential type sensor based on Gd2Zr2O7 solid electrolyte coupling SmSbO4 sensing electrode

Propionaldehyde, a volatile industrial chemical, poses significant environmental and health risks due to its toxicity. To address the need for sensitive and reliable detection of this compound, we developed a mixed potential sensor with an efficient triple phase boundary, employing a Gd2Zr2O7 solid electrolyte and a SmSbO4 sensing electrode. The sensor's optimal sensitivity to propionaldehyde was achieved at a working temperature of 560 degrees C, with a remarkably low detection limit of 0.2 ppm-far beneath the safe environmental threshold for propionaldehyde. The sensor's response demonstrated a linear relationship with Propionaldehyde concentrations between 0.2 and 2 ppm, and a logarithmic linear relationship within the 2-100 ppm range. Based on the linear fitting line, the sensor's sensitivities in these ranges were -8.7 mV/ppm and -59.7 mV/decade, respectively. This sensor behavior aligns with the mixed potential sensing mechanism. The sensor's robust repeatability, humidity resistance, selectivity, and long-term stability underscore its reliability for practical applications, making it a valuable tool for effective environmental monitoring of propionaldehyde concentrations.