Visible-light photocatalytic activity of semiconductor composites supported by electrospun fiber

The preparation and photocatalysis of TiO2–ZnS/fluoropolymer fiber composites were investigated. The fluoropolymer nanofiber mats with carboxyl groups were prepared by electrospinning, and then titanium and zinc ions were introduced onto the fiber surfaces by the coordinating of carboxyl of fluoropolymer in solution. The TiO2–ZnS composites with diameters 15 nm to 1 μm were immobilized on the surface of fluoropolymer electrospun fiber using hydrothermal synthesis. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis reveal that some chemical interaction exists between TiO2–ZnS composites and fluoropolymer fibers, so the semiconductor composites were immobilized tightly on the surface of fluoropolymer fibers. The ultraviolet–visible absorption spectra show the TiO2–ZnS/fluoropolymer fiber composites have low band gap and good visible-light response ability. The degradation rate of methylene blue in TiO2–ZnS/fluoropolymer fiber composites system was considerably higher than that of TiO2 or TiO2–ZnS nanoparticles system under visible-light irradiation, because the TiO2–ZnS/fluoropolymer fiber composites possess good visible-light response ability, high specific surface areas, and adsorption–migration–photodegradation process. The photocatalytic activity of TiO2–ZnS/fluoropolymer fiber composites changes indistinctively after 10 repeating photocatalysis tests.