Applied Surface Science, Vol.456, 808-816, 2018
Vertically aligned MoS2/ZnO nanowires nanostructures with highly enhanced NO2 sensing activities
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 degrees C and 200 degrees 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 200ppb. 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.
Keywords:ZnO nanowires array;Molybdenum disulfide (MoS2) nanosheets;Core-shell structure;Chemical vapor deposition;Gas sensing activities;Modulation of depletion layer