A novel flexible acetylene gas sensor based on PI/PTFE-supported Ag-loaded vertical ZnO nanorods array

The paper presents a novel flexible acetylene gas sensor consisting of Ag-loaded vertical ZnO nanorods (NRs) supported by a polyimide/polytetrafluoroethylene substrate. The fabricated sensor exhibits a high response magnitude of 27.2 (1000 ppm), short response/recovery time of 62/39 s, and broad detection range from 3 to 1000 ppm at a low operating temperature of 200 °C. The enhancement of sensing performance was mainly attributed to the large effective surface area, small grain size, ordered arrays of ZnO NRs, and the successful immobilization of tiny sized Ag nanoparticles. At optimum conditions (8 s Ag-loaded ZnO NRs at 200 °C), the sensor showed a negligible response degradation of ∼2.1% at a curvature angle of 90°, and ∼8% for 5 × 104 bending/relaxing cycles. The outstanding flexibility of the as-fabricated sensor ensured stable sensing performances to extreme bending stress, indicating the possibility of fabricating highly efficient and practical flexible C2H2 gas sensors.