Solid state electrolyte type formaldehyde (HCHO) gas sensors based on a novel pyrochlore structure Gd₂Zr₂O₇ solid electrolyte coupled with rod-shaped ZnO sensing electrode (SE) were initially designed and fabricated in this paper. The incorporation of alkaline-earth metal Ca can significantly improve sensing performance of the Gd₂Zr₂O₇ based sensors to HCHO. The response value (ΔV) of the sensors based on Gd_2-xCa_xZr₂O₇ (x = 0, 0.02, 0.05 and 0.1) varied approximately linear with the logarithm of HCHO concentration in the range of 1-100 ppm at 600 °C, with sensitivities of -25, -30, -15 and -5 mV/decade, respectively. The optimal sensor based on Gd_1.98Ca_0.02Zr₂O₇ (GCZ(0.02)) exhibited the excellent sensing characteristics with maximum response value (-61.3 mV) and extremely short response time (3 s) to 100 ppm HCHO. In addition, the GCZ(0.02) sensor also showed good selectivity and stability within 20-day period of continuous high-temperature aging under high-humidity condition. Conclusively, the sensing behavior and mechanism based on mixed potential were investigated and demonstrated by the mearsurement of the polarization curves.

本文首先设计和制造了一种基于新型烧绿石结构Gd ₂ Zr ₂ O ₇固体电解质和棒状ZnO传感电极（SE）的固态电解质型甲醛（HCHO）气体传感器。掺入碱土金属Ca可以显着改善基于Gd ₂ Zr ₂ O ₇的传感器对HCHO的传感性能。基于Gd _2-x Ca _x Zr ₂ O ₇的传感器的响应值（ΔV）（x = 0、0.02、0.05和0.1）在600°C下与HCHO浓度的对数在1-100 ppm范围内呈近似线性变化，灵敏度为-25，-30，-15和-5 mV /十倍， 分别。基于Gd _1.98 Ca _0.02 Zr ₂ O ₇（GCZ（0.02））的最佳传感器具有出色的感测特性，具有最大响应值（-61.3 mV）和对100 ppm HCHO的极短响应时间（3 s）。此外，GCZ（0.02）传感器在高湿度条件下连续高温老化20天期间也显示出良好的选择性和稳定性。最后，通过极化曲线的测量研究并证明了基于混合电势的传感行为和机理。