Ultra-selective and stable ethylene detection via exsolution of catalytic Ni nanoparticles in chemiresistive gas sensors

Abstract

Ethylene, a gaseous indicator that provides critical information about plant aging, is biologically active in plants, even at trace levels. Therefore, it must be precisely monitored and controlled at sub-ppm levels. However, the accurate detection and clear identification of ethylene has been a major challenge, owing to its low chemical reactivity and severe interference with other gases, including water vapor. In this study, we devised a novel sensor capable of detecting even trace amounts of ethylene using ZnO nanoflowers embedded with exsolved Ni nanocatalysts. It completely removed interferents via catalytic oxidation and exhibited remarkable gas selectivity (approximately 60 and 32 to 1 and 0.2 ppm ethylene, respectively) and an excellent stability against humidity variations. Furthermore, owing to robust metal-support interactions in the nanocatalysts, the sensor exhibited excellent thermal stability and reliable long-term sensing performance at elevated temperatures. This study provides an approach for facilitating the successful commercialization of ethylene detectors.