Acetone detection at low temperature using a gas nano-sensor based on ZnO flakes loaded with metal organic-skeleton ZIF-8

Timely detection of gases that are toxic, flammable, polluting, or otherwise harmful is essential for human health. Unfortunately, gas sensors based on a single metal oxide suffer from low sensitivity and poor selectivity, which is suitable neither for practical applications nor industrial development. Therefore, there is an urgent need to develop a gas sensor with excellent sensitivity and good selectivity. In the study reported here, heterostructured ZIF-8/ZnO nanosheets were prepared as gas-sensitive materials by a simple hydrothermal method, and the self-stacking of ZnO nanosheets was lessened by the loading effect of ZIF-8 for improved gas sensitivity when detecting acetone. The results show that the sensitivity of the ZIF-8/ZnO sheet structure reaches 78.6 for 50 ppm acetone at 100 °C, which is nearly four times that of pure ZnO sheets. Meanwhile, with short response and recovery times (9 s and 4 s, respectively) and excellent selectivity and stability, the ZIF-8/ZnO sheet structure is suitable for practical applications. This enhancement effect is attributed to the supporting filtering effect of ZIF-8, which is carried in between the ZnO nanosheets and acts as an electron transport channel, reducing the accumulation of ZnO nanosheets and accelerating the electron transport rate. This provides a new idea for the future detection of acetone gas.