The rapid detection for methane of ZnO porous nanoflakes with the decoration of Ag nanoparticles

Realizing the real-time detection of CH4 is important for the safety of human life. A facile hydrothermal method was used to synthesize Ag nanoparticles-decorated ZnO porous nanoflakes (PNFs) in this study. The characterization results confirmed that Ag nanoparticles had been decorated in ZnO nanoflakes with the thickness of ∼10 nm. The gas-sensing properties of Ag-decorated ZnO nanoflakes were also investigated. While the gas-sensing performances of ZnO were remarkably improved by decorating Ag nanoparticles on the surface of ZnO nanoflakes, the response of the Ag-decorated ZnO sensor to 3000 ppm CH4 is almost 1.3 times as high as that of pristine ZnO sensor. The obtained Ag/ZnO sensor exhibits better long-term stability and shorter response recovery time (5/38 s) in the comparison with pristine ZnO, demonstrating the possibility for the actual detection of CH4. The enhanced CH4 sensing performance can be attributed to the synergism between the unique hierarchical porous structure and the sensitizing actions utilized by the Ag nanoparticles.