Fabrication of TiO2/ZnO composite nanofibers by electrospinning and their photocatalytic property

TiO2/ZnO composite nanofibers with diameters in the range of 85-200 nm were fabricated via the electrospinning technique using zinc acetate and titanium tetra-isopropoxide as precursors, cellulose acetate as the fiber template, and N,N-dimethylformamide/acetone 1:2 (v/v) mixtures as the co-solvent. After treated with 0.1 mol/L NaOH aqueous solution, TiO2/zinc acetate/cellulose acetate composite nanofibers were transformed into TiO2/Zn(OH)(2)/cellulose composite nanofibers. TiO2/ZnO composite nanofibers were obtained by calcinating the hydrolyzed composite fibers at 500 and 700 degrees C for 5 h. The structure and morphology of composite nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. with the blending of ZnO into TiO2, a new crystallite ZnTiO3 was formed in addition to the ZnO and TiO2 crystallites, and the ultraviolet light absorption efficiency was enhanced according to the UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of TiO2/ZnO composite nanofibers toward the decomposition of Rhodamine B and phenol was investigated. Almost 100% Rhodamine B and 85% phenol were decomposed in the presence of TiO2/ZnO composite nanofibers under mild conditions. The results demonstrated that the blending of ZnO in the TiO2/ZnO composite nanofibers increased the photocatalytic efficiency. The optimum ZnO content in the TiO2/ZnO composite nanofibers was 15.76 wt% to reach the most efficient photocatalytic activity. A schematic diagram of photocatalytic mechanism of TiO2/ZnO composite nanofibers was also presented. (C) 2010 Elsevier B.V. All rights reserved.