Vertically aligned MoS2/ZnO nanowires nanostructures with highly enhanced NO2 sensing activities

Abstract

Molybdenum disulfide/ZnO nanowires (MoS2/ZnONWs) nanostructures with highly enhanced gas sensing activities to NO2 were fabricated in present study. The MoS2 nanosheets with a vertically aligned structure were fabricated by sulfurization of direct-current (DC)-magnetic-sputtering Mo films on ZnO nanowires, and a hydrothermal reaction was utilized to synthesize ZnONWs. MoS2/ZnONWs nanostructures with different thicknesses were assessed for gas-sensing performances with exposure to NO2 in different condition such as room temperature, 100 °C and 200 °C. The results show that, compared to as-prepared MoS2 nanosheets and ZnONWs, the MoS2 nanosheets on ZnONWs have exhibited excellent sensitivity, recovery, repeatability, selectivity and as a function of working temperatures, with a low detection concentration of 200 ppb. Further, the enhancement mechanisms of MoS2/ZnONWs nanostructures were attributed to band bending and modulation of the depletion layer width created at the interface of MoS2 and ZnO. The synthesized MoS2/ZnONWs nanostructures explored a way for efficient, high responsive, and stable sensors to NO2.