Ultrafine hollow TiO2 nanofibers from core-shell composite fibers and their photocatalytic properties

The oxidized electrospun polyacrylonitrile (o-PAN) fibers are used as templates and formed core-shell composite fibers by coating a layer of TiO2 sol. After calcination in air, hollow TiO2 nanofibers (HTONFs) are fabricated by removing the PAN fibrous template for the photocatalyzed degradation of methylene blue (MB). Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectra are used to characterize the morphologies and structures of HTONFs. The effects of MB concentration, amount of TiO2, light intensity, pH and calcination temperatures on the reaction rate constant are investigated. At last, HTONFs is recycled by a simple method, and the reutilization for photocatalyzation is evaluated.