Room-temperature highly sensitive CO gas sensor based on Ag-loaded zinc oxide/molybdenum disulfide ternary nanocomposite and its sensing properties

摘要

A new ternary nanocomposite of Ag-loaded zinc oxide (Ag-ZnO)/molybdenum disulfide (MoS_2) was successfully prepared via layer-by-layer (LbL) self-assembly method for carbon monoxide (CO) sensing application. The microstructure and micromorphology of Ag-ZnO/MoS_2 nanocomposite were fully characterized by various analytical techniques. The gas-sensing properties of the Ag-ZnO/MoS_2 nanocomposite film were investigated upon exposure to different CO concentrations at room temperature, and compared with the pure ZnO, ZnO/MoS_2 and Pt-ZnO/MoS_2 sensors. The experimental results indicated that the Ag-ZnO/MoS_2 nanocomposite sensor has excellent response, swift response/recovery characteristics, as well as acceptable repeatability and selectivity, which outstripped that of pure ZnO, ZnO/MoS_2 and Pt-ZnO/MoS_2 film sensors. The underlying sensing mechanism of Ag-ZnO/MoS_2 nanocomposite film was attributed to catalytic activity of Ag and synergistic effect of ZnO and MoS_2. This work demonstrated the Ag-ZnO/MoS_2 is an excellent candidate for constructing room temperature CO gas sensor.