Large Scaled Synthesis of Heterostructured Electrospun TiO₂/SnO₂Nanofibers with an Enhanced Photocatalytic Activity

Heterostructured TiO 2 /SnO 2 fibrillar nanocomposites were synthesized by using electrospinning technology with the setup composed of a syringe pump with two parallel syringes on it and a rotating collector. The heterojunctions were formed between TiO 2 and SnO 2 nanofibers fast and efficiently on a large scale, after the fiberizing carrier polyvinylpyrrolidone (PVP) on the as-spun composite nanofibers was burnt away at 500°C. The samples were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflection spectroscopy (DRS), and photoluminescence spectra (PL), respectively. The results indicated that two kinds of small nanofibers with different diameters were interconnected to form heterojunctions. Photocatalytic tests displayed that the heterostructured TiO 2 /SnO 2 nanofibers exhibited a much higher degradation rate of methylene blue (MB), rhodamine B (RhB), and 4-chlorophenol (4-CP) than that of bare TiO 2 nanofibers or Evonik P25 under UV light irradiation. The enhanced photocatalytic activity could be attributed to the effective charge separation derived from the coupling effect of TiO 2 and SnO 2 nanocomposites.