Summary
Vanadium oxide fibres are attractive for gas sensing, and electrospinning combined with sol–gel chemistry offers a simple route to make them. In this work, composite vanadium oxide (VOx)-based fibres were synthesised by electrospinning using poly(vinyl acetate) (PVAc) as a polymeric binder and vanadium oxytriisopropoxide as the vanadium precursor, then studied as-spun and after calcination between 300 and 500°C. The microstructure and composition were characterised in detail by scanning electron microscopy, thermogravimetry, reflectance FTIR, micro-Raman spectroscopy and photoluminescence, with an eye to gas-sensor fabrication. The analysis shows that V2O5/PVAc fibres are formed, and that calcination gradually removes the PVAc and drives structural rearrangement that changes the fibre morphology. As the calcination temperature rises, the V2O5 crystallinity improves while a more oxygen-deficient, substoichiometric surface layer develops — behaviour directly relevant to sensing performance.