Photoluminescence properties of TiO 2 nanofibers

Multi-walled carbon nanotube (MWCNT)-TiO 2 nanofiber (NF) composites forming a layered nanostructure (MWCNTs/TiO 2 NFs/Ti) were prepared by impregnation at low temperature. Room temperature photoluminescence (PL) of these nanostructures shows a broad intense band in the visible light range (∼450–600 nm). The origin of the PL emission which, mainly, resulted from surface oxygen vacancies and other defects was investigated. We studied the effect of MWCNT deposition on the PL of TiO 2 NFs where the MWCNTs can act as an electron reservoir of electrons emitted from TiO 2 nanofibers when irradiated with UV light. The combination of MWCNTs and TiO 2 results in quenching of TiO 2 luminescence in the visible range. In addition, the prepared surface of MWCNTs-TiO 2 was irradiated with Ti + ions using irradiation energy of 140 keV and doses of 10 13 ions/cm 2 . Also, this treatment induced the PL intensity quenching due to the generation of non-radiative additional levels inside the band gap. Graphical abstract ᅟ