Synthesis of nanometer-size Bi3TaO7 and its visible-light photocatalytic activity for the degradation of a 4BS dye.

Most of tantalate photocatalysts are mainly synthesized by solid-state (SS) reaction methods and only show photocatalytic activity under UV light irradiation. Ta(2)O(5) as a raw material shows an extremely high chemical stability, limiting its application to a few systems. A novel nanometer Bi(3)TaO(7) photocatalyst was synthesized by a facile and low-cost sol-gel method using Ta(2)O(5) and Bi(NO(3))(3)·5H(2)O as the Ta and Bi sources, respectively. The as-obtained samples were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy (DRS) and Fourier transform infrared spectroscopy (FT-IR). The band gap energy of the as-obtained nanometer Bi(3)TaO(7) photocatalyst was determined to be about 2.75-2.86 eV. The Bi(3)TaO(7) nanopowders show a strong adsorbability and a high visible-light photocatalytic activity for the degradation of 4BS, which can be ascribed to the surface physicochemical properties and structure of the Bi(3)TaO(7) nanometer catalyst. The degradation of 4BS is attributed to the photocatalysis but not to the adsorption of 4BS on the as-prepared catalyst.