Fabrication of WS2 nanofibers from WO3 nanofibers prepared by an electrospinning method

This paper describes a procedure of synthesizing long WS2 nanofibers. WO3 nanofibers were prepared as precursors by electrospinning of ammonium meta-tungstate (AMT), polyvinyl alcohol (PVA) and alcohol solution followed by calcination at 550 degrees C in air. WS2 nanofibers were obtained by sulfurization of the WO3 nanofibres at 800 degrees C in an argon atmosphere, with sulfur powder acting as sulfuration reducer. The nanofibres were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). The results show that the final products are pure WS2 nanofibres, which have high aspect ratio. The WS2 nanofibers with rough surface were formed of nanoparticles, while some nanoflakes appeared on the surface of WS2 nanofibres. The diameters of the WS2 nanofibers were between 200 and 300 nm, which is similar to WO3 nanofibers. In addition, the WS2 nanofibers were polycrystalline.