Gas sensing properties under UV radiation of In₂O₃ nanostructures processed by electrospinning

Manufacturing In₂O₃/PVP fibers, by sol–gel method coupled with the electrospinning technique, have been obtained In₂O₃ nanostructures. The morphological and microstructural properties of as spun and annealed samples have been examined using Thermo Gravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC), X-Ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM). Characterization results provided clear indications of the formation of different In₂O₃ nanostructures after annealing by changing the solvent system utilized for the electrospinning process. The sensing characteristics of the In₂O₃ nanostructures synthesized have been evaluated for the monitoring of nitrogen dioxide at room temperature in the dark, under continuous ultra-violet (UV) illumination and under pulsed UV illumination (provided only during the recovery time). The effect of In₂O₃ nanostructure morphology and UV radiation has been investigated and discussed. The better sensing performances (high response and very short recovery time) were registered when the sensors were irradiated with pulsed UV light. - Highlights: • Preparation and synthesis of In₂O₃ nanostructures by electrospinning. • Physical and chemical characterization of prepared samples. • Investigation of the sensing properties to monitor NO₂ at RT under pulsed UV light