Gas sensors based on ZnO/silk fibroin film for nitrogen dioxide detection under UV light at room temperature

In this work, a novel gas sensor based on ZnO/silk fibroin (ZnO/SF), which was synthesized by the hydrothermal method, was proposed for efficient and fast detection of NO2 gas under the irradiation of 365 nm UV-light at room temperature. The prepared ZnO/SF sensor activated by UV showed a high sensing response of about 85 towards 20 ppm NO2 gas at room temperature with an average response and recovery time of 26 s and 16 s, respectively. Test results of 1 ppm, 5 ppm, 10 ppm, 20 ppm NO2 gas indicated that the ZnO/SF sensor had a very excellent response and linearity. Additionally, the sensing mechanism was analyzed as well.