Construction And Characteristics Of Bismuth Tungstate-based One-dimensional Nanostructures With Photocatalysis-Luminescence Bifunctionality

In recent years, semiconductor heterogeneous photocatalytic technology, as a new pollution treatment technology, shows a wide application prospect in sewage treatment and water in-depth treatment. Bismuth tungstate, as one of the simplest members of the layered Aurivillius family with a narrow band gap of 2.75 eV, has been considered as the potential semiconductor photocatalytic materials responded to the visible light. In order to further improve performance of bismuth tungstate, numerous methods have been adopted to modify the photocatalysts, such as doping of metal or nonmetal elements, surface modification and coupling with other semiconductors, which have become one of the popular research subjects in the realm of photocatalytic technology.In this thesis, Bi₂WO₆:Er³⁺ nanobelts and Bi₂WO₆:RE³⁺（RE=Er, Yb/Er, Eu） nanofibers were prepared via electrospinning process. The samples were systematically characterized by modern measurement techniques, including X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive spectrometry（EDS）, Brunauer-Emmett-Teller（BET） method, photoluminescence spectroscopy（PL）, UV-Vis diffusion reflectance spectroscopy（UV-Vis DRS） and photocatalytic testing. The results show that the as-formed Bi₂WO₆:RE³⁺ nanofibers or nanobelts are the orthorhombic system, and the mean diameter of nanofibers, the width of nanobelts and the thickness of nanobelts are approximately 120 nm, 1.0 μm and 116 nm, respectively. The photocatalytic activities of all products are evaluated by degradation of rhodamine B（RhB） under simulated solar light irradiation. The light source is a Xenon lamp（300 W, 300-2500 nm）. The photodegradation efficiency of Bi₂WO₆:RE³⁺（RE=Er, Yb/Er, Eu） nanofibers reaches up to more than 88 % with the maximum of 99.6 % after 120 min under simulated solar light irradiation; the photodegradation efficiency of Bi₂WO₆:Er³⁺ nanobelts reaches 99 % after 100 min. Bi₂WO₆:RE³⁺ nanomaterials possess excellent photoluminescence and photocatalytic activity.