Low-temperature NO2 sensor based on ZnO/CuO heterostructure for precision agriculture

Bi-MOF-derived CuO/ZnO heterojunctions were made by ion exchange. • The sensor reaches 10 ppb detection and 5.08-fold higher response than ZnO. • It maintains a 6.38 response to 1 ppm NO 2 at −20 °C. • Quantitative NO 2 monitoring is demonstrated for precision agriculture. The development of miniaturized and portable NO 2 sensors for agricultural environments, capable of operating at low temperatures, is of great scientific significance and application value for improving nitrogen fertilizer utilization efficiency and preventing environmental pollution. ZnO/CuO heterostructures were prepared by employing bimetallic-based metal–organic frameworks (Bi-MOFs) as self-sacrificial templates for enhanced NO 2 sensing at room and lower temperatures in the field of precision agriculture applications. Our experiments reveal that the ZnO/CuO heterostructure calcined at 400 °C exhibits a response approximately 5.08 times that of pure ZnO. It delivers a response value of 7.78 toward 1 ppm NO 2 at 20 °C, with response and recovery times of 70 s and 150 s, respectively. Furthermore, it exhibits an excellent detection limit as low as 10 ppb toward NO 2 . Notably, even at − 20 °C, its response to 1 ppm NO 2 remains at 6.38. The excellent gas-sensing performance can be attributed to the synergistic contribution of the mesoporous structural advantages of MOF-derived MOS and heterostructures. This work provides promising research ideas and strategies for the application of Bi-MOF-derived MOS heterostructures in gas sensing. Download: Download high-res image (208KB) Download: Download full-size image