Pillared Nanocomposite TiO2/Bi-Doped Hexaniobate with Visible-Light Photocatalytic Activity

Under the strategies of doping to extend the absorptive response region of a semiconductor and fabricating a heterojunction structure to suppress the recombination of the photogenerated electron hole pairs, a TiO2-pillared Bi-doped hexaniobate nanocomposite was prepared via a solid state reaction and a subsequent exfoliation-restacking route. The as-prepared pillared nanocomposite was characterized by powder X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, UV-vis, and N-2 adsorption-desorption measurements. It was revealed that the host 2D sheet structure was retained after doping, exfoliation, and restacking. The pillared nanocomposite is mesoporous with a high specific surface area (more than 110 m(2)/g) and shows a good photocatalytic activity in the degradation of methylene blue under visible light irradiation. A photoexcitation model in the semiconductor semiconductor pillared photocatalyst was proposed based on the results of XPS, UV-vis, and photoelectrochemical studies.