Eu-doped titania nanofibers by electrospinning

Pure and Europium-doped titania nanofibers weresuccessfully fabricated by the electrospinning technique,using for the first time a single multielementTitanium/Europium source. Eu content was 5 %mol.Microstructure was studied by means of scanningelectron microscopy (SEM), thermal behaviourfollowed by thermogravimetric and differential thermalanalysis (TG-DTA). Phase analysis was performed bymeans of X-ray diffraction (XRD) and high temperatureX-ray diffraction analysis (HT-XRD) up to 1100°C. Luminescence measurements were performed using alaser excitation source at 395 nm. All electrospunmaterials consisted of randomly oriented nanofibers of afairly uniform diameter. The average fiber size was80±20 nm and 40±10 nm for, respectively, Eu-dopedand undoped TiO2 calcinated at 500°C. The presence of Europium shifted toward higher values either thecrystallization temperature of anatase and the anatase torutile phase transition, the latter being accompanied bythe formation of the EuTi2O7 phase. The doped samplesshow a strong luminescence of Eu3+ ions. The emissionspectra are dominated by the 5D0→7F2 emission,suggesting a notable distorsion around the Eu3+ ions.The broadening of the bands points to the presence of arelevant inhomogeneous disorder around the Eu3+ sites.