Tungsten Sulfide Nanoflakes: Synthesis by Electrospinning and Their Gas Sensing Properties

Tungsten sulfide (WS) nanoflakes were successfully prepared via electrospinning with polyvinylpyrrolidone (11/1)) as organic solvent. In addition, Ag-deposited WS2(Ag-WS) was obtained by chemical blending/calcination method. The structure and morphology of as -prepared materials were characterised by powder X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The XRD result shows that the prepared WS2 has a graphene-like structure with P-63/mmc, space group symmetry. The SEM illuminates that the sensing samples have nanoflake appearance. Furthermore, heater-type gas sensors were fabricated based on WS2 and Ag-WS2 nanomaterials. The sensing responses of WS, and Ag-WS, on the ammonia (N11), ethanol (C2H501-1), and acetone (C31-160) were investigated at about 220 C. The results indicate that gas sensor based on WS, and Ag-WS, nanoflakes has 60 ppm sensing threshold value for ammonia. One possible gas sensing mechanism of WS2 and Ag-WS, gas sensors is surface control via charge transfer.