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

•Ag-ZnO/MoS2 ternary composite was fabricated by layer-by-layer self-assembly route.•Sensing properties of Ag-ZnO/MoS2 nanocomposite toward CO gas were investigated.•The underlying sensing mechanism of Ag-ZnO/MoS2 nanocomposite film was discussed. A new ternary nanocomposite of Ag-loaded zinc oxide (Ag-ZnO)/molybdenum disulfide (MoS2) was successfully prepared via layer-by-layer (LbL) self-assembly method for carbon monoxide (CO) sensing application. The microstructure and micromorphology of Ag-ZnO/MoS2 nanocomposite were fully characterized by various analytical techniques. The gas-sensing properties of the Ag-ZnO/MoS2 nanocomposite film were investigated upon exposure to different CO concentrations at room temperature, and compared with the pure ZnO, ZnO/MoS2 and Pt-ZnO/MoS2 sensors. The experimental results indicated that the Ag-ZnO/MoS2 nanocomposite sensor has excellent response, swift response/recovery characteristics, as well as acceptable repeatability and selectivity, which outstripped that of pure ZnO, ZnO/MoS2 and Pt-ZnO/MoS2 film sensors. The underlying sensing mechanism of Ag-ZnO/MoS2 nanocomposite film was attributed to catalytic activity of Ag and synergistic effect of ZnO and MoS2. This work demonstrated the Ag-ZnO/MoS2 is an excellent candidate for constructing room temperature CO gas sensor.