Enhanced visible-light-driven photocatalysis of surface nitrided electrospun TiO2 nanofibers

Abstract

Enhanced visible-light-driven photocatalysis of TiO₂ nanofibers have been prepared by the electrospinning method combined with a surface nitridation process. The visible-light-driven photo-catalytic activity of surface nitrided TiO₂ (N–TiO₂) nanofibers has been evaluated using rhodamine B indicator, and it was found that the visible-light-driven photocatalytic activity of the electrospun TiO₂ nanofibers could be enhanced by nitridation in NH₃ atmosphere. The optimal visible-light photocatalytic activity of N–TiO₂ nanofibers exceeded that of pure TiO₂ nanofibers by a factor of more than 12. The nitridation temperature under NH₃ flow was found to play an important part in the performance of N–TiO₂ nanofibers, and the optimum temperature is 500 °C. Structure, morphology and photoluminescence of these nanofibers were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM) and photoluminescence (PL) spectroscopy. The mechanism of the enhancement of visible-light-driven photocatalytic activity by surface nitridation has been discussed.