Mixed-potential solid-electrolyte (MPSE) gas sensors have important applications for the detection of hazardous NO₂. However, limited by the poor conductivity of conventional electrolytes at low temperatures, the realization of high performance of MPSE gas sensors usually requires a compromise to high working temperatures, hindering their application. To this end, we developed a novel ultrasensitive and selective MPSE NO₂sensor based on K₂Fe₄O₇solid electrolyte and Ni-MOF|N₂sensing electrode (SE), which can achieve a low detection limit (LOD) as low as 5 ppb at room temperature (RT) without additional energy supply. Simultaneously, the selectivity of the sensor to the interfering gas NO achieves a 31-fold improvement by the enhanced participation of H₂O molecules and unsaturated coordinated Ni ions, which are obtained by the sintering in anoxic atmospheres like N₂or Ar. Moreover, the sensor is further used as the information collection terminal of the Internet of Things (IoT) system, building a NO₂monitoring network for remote monitoring, different environment evaluation, and information sharing. This work fills the gap of the ultrasensitive MPSE NO₂sensor in the RT field and provides new insights for the construction of NO₂portable sensor networks.

原文链接：https://www.sciencedirect.com/science/article/pii/S0925400523006585?via%3Dihub