Electrospinning-based (N,F)-co-doped TiO2-δ nanofibers: An excellent photocatalyst for degrading organic dyes and heavy metal ions under visible light

Abstract

Photocatalysis is one of the effective methods to alleviate the urgent pressure on energy shortage and environmental pollution in modern world, for which TiO2 has attracted great attention due to its excellent photocatalytic activity, high stability, non-toxicity and low cost. However, the wide band gap (about 3.2 eV), easy recombination between photogenerated electrons and holes, as well as easy agglomeration and difficult recycling of traditional nanomaterials limit its wide application. Herein, novel (N,F)-co-doped TiO2-δ nanofibers were successfully prepared simply by thermally treating electrospun nanofibers under Ar atmosphere using polyacrylonitrile as the reductive agent, tetrabutyl titanate as the titanium source and trifluoroacetic acid as the fluorine source. The resultant product can be directly used as photocatalysts for degrading environmental pollutants, which can remove 27.2% of rhodamine B, 40.9% of methylene blue and 31% of Cr(VI) within 60 min under visible light irradiation from a 5 W LED lamp, being almost 11.8, 3.2 and 2.8 times those over its commercially available TiO2 counterpart, respectively. The present work will provide a simple strategy to feasibly prepare various high-performance photocatalysts.