Compound Modification Of Bi₂WO₆ Photocatalyst And Investigation On Their Degradation Properties

Nowdays, seriously destructive and environmental pollution has become a major threat to humans’ lives as the high-speed development of society and industry. Herein, environmental management has been a significant direction of scientific research. Photocatalysis possesses a number of advantages such as room-temperature oxidation for contaminant, smaller secondary pollution, low-cost and light energy conversion, which is suited and potential for the degradation of contaminant. Bi₂WO₆ is one of photocatalysts with visible light response. Based on the nice stability and suitable energy band structure of Bi₂WO₆, a lot of relative researches have been reported. In conclusion, the preparation of novel efficient photocatalyst satisfying with environmental requirements has been the key point of recent research for enhanced photocatalytic performance.Bi₂WO₆ hierarchy consisted of porous lamella with optimum density has been prepared successfully via adjusting parameter optimization of solvothermal method in this thesis. In addition, Bi₂WO₆ is modified by combining with organic substance. According to XRD, UV-vis, SEM, TEM, XPS, PL, PC and degradation test, the structure, photocatalytic performance and structure-function relationship of various semiconductor was studied and analyzed, demonstrating reasonable growth and reaction mechanism.Hierarchical Bi₂WO₆ flower-like sphere assembled by porous lamella was prepared through adjusting solvents components, reactant ratio, reaction temperature and time. And then the effect of experimental parameter for Bi₂WO₆ growth and morphology was discussed in detail. Finally, the optimum parameter was ascertained based on abovementioned results.Bi₂WO₆ was modified via combining with macromolecule polyacrylonitrile（PAN） resulting in Bi₂WO₆-PAN（BP） composite. Organic macromolecule anchored on Bi₂WO₆ lamella surface change the way of orientational arrangement and self-assembly, leading to the fabrication of 1D Bi₂WO₆ rods with 0.2-2 mm diameter. The organic substance on Bi₂WO₆ surface as active sites inhibits the recombination of carriers, leading to enhanced photocatalytic performance of Bi₂WO₆.Bi₂WO₆ was modified via the confined space effect of 2D MoS₂-RGO（MG） substrate which refrained the growth of Bi₂WO₆. Bi₂WO₆ nanocrystals with 5-20 nm size limited by narrow space between interlamination anchored on MG, constructing nanosized heterojunction. This heterojunction inhibited the recombination of carriers, resulting in enhanced photocatalytic performance for Cr（Ⅵ） reduction.