Abstract:

The construction of TiO2with a special architecture to enhance the photocatalytic property of nano-titanium dioxide (TiO2) was achieved by synthesizing a three-dimensional (3D) network TiO2 nanowire film (W-film) on the surface of Ti foil using a hydrothermal method. Samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Results showed that the three-dimensional network nanowire film was composed of many randomly-oriented anatase nanowires, which had diameters of 10-30 nmand lengths larger than 5 μm. Optical properties of these W-films were studied by UV-Vis spectrophotometry (UV-Vis). The results indicated that the absorbency of the W-film was higher than that of a particulate film (P-film) in the 350-700 nm region and the absorption edge was red-shifted. Meanwhile, the absorbency of the W-film increased as the hydrothermal time increased. After further investigation of the photoelectrochemical properties of the W-film in Na2SO4 solution, we determined that the photoelectrochemical properties of the W-film were better than those of P-film. Methyl orange was used as a target molecule to estimate the photocatalytic activity of the W-film. Under the same testing conditions, the catalytic efficiency of the W-film was found to be 2.3 times as that of the P-film and it, therefore, has a bright future. This kind of composited W-film electrode possesses advantages both in flexibility and implementation of the applied potential, which will increase the application field of this TiO2 film.

Key words: TiO2, Nanowire, Thin film, Hydrothermal method, Titaniumfoil