Electrical and Morphological Characterization of TiO₂ Electrospun Nanofibers

Titanium oxide nanofibers were successfully prepared via thermal treatment of electrospun composite polymer (PVP)/TiO₂ nanofibers. The morphology and crystal structure were characterized by SEM and TEM. It was confirmed that the calcination process was responsible for the removal of PVP component and the growth of crystalline TiO₂. The resulting nanofibers, which have a quite rough surface, an average diameter of 60 nm and a length reaching hundreds of μm, were found to be formed by the agglomeration of TiO₂ nanoparticles with brookite phase. Gas-sensing tests towards ethanol demonstrated n-type sensing response and good reversibility at an operating temperature of 450 °C. A first tentative to model electrical impedance spectra was made in order to understand charge transport in relationship with morphological and structural aspects.