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

Abstract

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 N2 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 m2/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.