Fabrication of WO3 nanofibers by high voltage electrospinning

Mixtures of 0.1, 0.3, and 0.5 mmol ammonium metatungstate hydrate (AMH), and poly (vinyl alcohol) (PVA) were electrospun by a + 20 kV direct voltage to synthesize fibers. Those of 0.5 mmol AMH were further calcined to have PVA removed and crystalline degree improved. At 500 °C and 2 h calcination, WO3 nanofibers, including two main stretching modes, 3.24 eV direct energy gap, and 378 nm wavelength violet emission were detected. A possible formation mechanism of WO3 nanofibers was proposed according to the experimental results.

► WO3 nanofibers as an n-type semiconductor.
► A lab-made electrospinning equipment enables us to form as-spun fibrous precursors.
► Upon calcination of the precursors at 500 °C, WO3 nanofibers were synthesized.
► The promising nanofibers for multiple potential applications.