Electrospun Cu-, W- and Fe-doped TiO2 nanofibres for photocatalytic degradation of rhodamine 6G

Titanium dioxide (TiO2), thanks to its interesting properties as non-toxicity, low cost and high chemical stability, has been extensively investigated for several applications in which, following light absorption, the generated charges can be usefully applied, as for photovoltaic systems and photocatalytic devices. However, due to the wide intrinsic energy gap of TiO2 (between 3.0 and 3.2 eV, depending on the crystalline structure), only a small fraction of the solar spectrum can be used to promote the electron-hole pair formation. In order to reduce the energy gap and, therefore, increase the fraction of the solar spectrum that can be absorbed, different approaches have been used, mainly by doping TiO2 with metals or anions. In this work we will present our results on the deposition, by means of the electrospinning technique, of TiO2 nanofibres doped with metals (iron, copper and tungsten). These nanofibres exhibit morphology at bundle structure composed by sheaths of about 300-nm diameter and core filled with 20-nm-thick fibrils. Metal-doped TiO2 nanofibres have been characterized by SEM, TEM, EDX, XPS and XRD for morphological, chemical and structural analyses, respectively. The effect of the metal concentration on the photocatalytic properties of these nanofibres have been investigated through the study of the degradation of a pollutant model (rhodamine 6G) by using visible lamp and sunlight as light source.