Enhanced photocatalytic activity of TiO <sub>2</sub> -CdS composite nanofibers under sunlight irradiation**
Muhsin A. Kudhier, Roonak Abdul Salam A. Alkareem, Raad S. Sabry
Abstract
Abstract Pure TiO 2 and TiO 2 -CdS composite nanofibers were synthesized through electrospinning technique. The effects of various levels of CdS loading in a TiO 2 nanofibers composite were investigated. Pure TiO 2 nanofibers were polycrystalline with an anatase phase, whereas anatase and wurtzite phases coexisted in the TiO 2 -CdS composite nanofibers, according to X-ray diffraction (XRD) measurements. Using field emission scanning electron microscopy (FESEM) and UV-Visible spectroscopy, the impacts of composite CdS nanoparticles with TiO 2 nanofibers were investigated. Pure TiO 2 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 (E g ) evaluated from UV-Visible spectroscopy reduced from a value of 3.70 eV for pure TiO 2 nanofibers to 1.70 eV for TiO 2 -1CdS nanofibers. Photocatalytic properties of pure TiO 2 and TiO 2 -CdS composite nanofibers were calculated by a methylene blue (MB) aqueous solution degradation under sunlight irradiation. The results revealed that TiO 2 -0.5CdS nanofibers have efficient photocatalytic activity of up to 98 % after only 60 min.