Specificity improvement of the YSZ-based mixed potential gas sensor for acetone and hydrogen sulfide detection

Abstract

In this paper, mixed potential gas sensor using yttria-stabilized zirconia (YSZ) solid electrolyte was developed for acetone and hydrogen sulfide detection. By adjusting the operating temperature and fabricating a double-sensing electrode gas sensor, the specificity of the device was effectively improved. At first, we successfully synthesized two kinds of sensing electrode materials NiAlGaO4 and Sm1.2Sr0.8CoO4 by sol-gel method. The sensor based on NiAlGaO4 sensing electrode and Pt reference electrode performed high sensing performances to both acetone and hydrogen sulfide (H2S). By controlling the operating temperature of the sensor, we successfully improved the specificity of the device to H2S against acetone at 700 °C. However, when measuring acetone, H2S was still a non-negligible influential factor. Hence, sensing electrode material Sm1.2Sr0.8CoO4 was used to replace Pt electrode and develop a double-sensing electrode gas sensor. Due to the similar sensing property to H2S and the difference to acetone between NiAlGaO4 and Sm1.2Sr0.8CoO4, the double-sensing electrode sensor performed a good specificity to acetone against H2S. The response of the double-sensing electrode sensor to 10 ppm acetone was 15 mV while approximated 0–10 ppm H2S. The low detection limit of the present device could reach 1 ppm and the sensitivity of the sensor was 21 mV/decade. The result of simulation exhaled breath measurement exhibits the sensors we fabricated have an enormous potential for non-invasive breath analysis.