Enhanced photocatalytic activity of TiO2-CdS composite nanofibers under sunlight irradiation**

Pure TiO2 and TiO2-CdS composite nanofibers were synthesized through electrospinning technique. The effects of various levels of CdS loading in a TiO2 nanofibers composite were investigated. Pure TiO2 nanofibers were polycrystalline with an anatase phase, whereas anatase and wurtzite phases coexisted in the TiO2-CdS composite nanofibers, according to X-ray diffraction (XRD) measure-ments. Using field emission scanning electron microscopy (FESEM) and UV-Visible spectroscopy, the impacts of com-posite CdS nanoparticles with TiO2 nanofibers were inves-tigated. Pure TiO2 nanofibers have a smooth surface with several microns in length and 21-48 nm in diameter, but when CdS nanoparticles are added, the surface becomes granular. The energy band gap (Eg) evaluated from UV-Visible spectroscopy reduced from a value of 3.70 eV for pure TiO2 nanofibers to 1.70 eV for TiO2-1CdS nanofibers. Photocatalytic properties of pure TiO2 and TiO2-CdS com-posite nanofibers were calculated by a methylene blue (MB) aqueous solution degradation under sunlight irradiation. The results revealed that TiO2-0.5CdS nanofibers have ef-ficient photocatalytic activity of up to 98 % after only 60 min.