Natural sunlight excited ZnO/ZIF-8 derivative NOx gas sensor and its application in automobile exhaust gas detection

Photosensitized metal oxide gas sensors have been a research hotspot in the field of gas sensors in recent years, the vast majority of related studies use the ultraviolet light as the excitation light source, there are relatively few related studies on the ceramic gas sensors using a single LED as the excitation light sources, and even fewer studies on using natural sunlight as the light excitation source. In this study, porous ZnO precursor particles were introduced into the channels of ZIF-8 to ensure the integrity of its skeleton after calcination, and ZnO/ZIF-8 derivative was prepared and used to construct gas sensors to detect NO x under the different excitation light source (the natural sunlight, 365 nm LED and xenon lamp). Compared with the test under darkness conditions, the operating temperature was reduced 70℃ under light excitation conditions, the gas-sensitive response of the gas sensor to 20 ppm NO x under the natural sunlight excitation was 7.48 times of the darkness conditions, and the measured detection limit was as low as 50 ppb. Under the excitation of natural sunlight, 365 nm LED or xenon lamp, the room temperature gas sensitive response to NO x gas could be achieved. The prepared gas sensor was used for the actual detection of NO x concentration in vehicle exhaust, which showed the attractive practicality and excellent detection sensitivity.