Efficient nitric oxide sensing on nanostructured La2MMnO6 (M: Co, Cu, Zn) electrodes.

Selective detection of nitric oxide (NO) is a challenge for automotive exhaust monitoring systems due to the instability of sensing architectures operating under extreme environments. Herein, yttria-stabilized zirconia (YSZ) solid-electrolyte-based electrochemical gas sensor was developed using double perovskite electrodes (DPO) for selective detection of NO. The La 2 MMnO 6 (M: Co, Cu, Zn) phases were synthesized by sol-gel processing of constituent salts and characterized for physicochemical and sensing properties to investigate the impact of transition metal cations present in octahedral environments on charge transport properties. The La 2 ZnMnO 6 with a predominant Zn2+–Mn4+ charge ordering excelled in the sensing characteristics with high sensitivity (33 mV/decade for 3–80 ppm NO concentration), fast response/recovery time (52/42 s) and significant NO selectivity at 500 °C. The sensing behavior of double perovskites was comprehensively explored and found to abide by the mixed-potential model. Moreover, stable sensing properties over a period of three weeks indicate the here-described sensors to be potentially competitive for onboard exhaust monitoring in automobiles. • Double perovskite oxide (DPO) electrodes for nitric oxide (NO) sensor. • La 2 ZnMnO 6 DPO shows sensitivity of 33 mV/decade for 3–80 ppm NO concentration. • Response/recovery time of 52/42 s and verified stability over 3 weeks. • Sensing mechanism explained by the mixed-potential model. [ABSTRACT FROM AUTHOR]