Direct Formation of Reusable TiO₂/CoFe₂O₄ Heterogeneous Photocatalytic Fibers via Two-Spinneret Electrospinning

A reusable photocatalytic TiO₂/CoFe₂O₄ composite nanofiber was directly formed by using a vertical two-spinneret electrospinning process and sol–gel method, followed by heat treatment at 550 °C for 2 h. The high photocatalytic activity of the composite nanofibers depends on the good morphology of the fibers and the appropriate calcination temperature. The crystal structure and magnetic properties of the fibers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The photocatalytic activity of the TiO₂/CoFe₂O₄ fibers was investigated through ultraviolet-visible absorbance following the photo-oxidative decomposition of phenol. Meanwhile, the presence of CoFe₂O₄ not only broadens the response region of visible light, but also enhances the absorbance of UV light. Furthermore, these fibers displayed photocatalytic activity associated with magnetic activity of CoFe₂O₄ ferrites, allowing easy separated of the photocata-lysts after the photo-oxidative process and effectively avoided the secondary pollution of the treated water.