【作者】 管美丽；

【导师】 黄少铭； 马德琨；

【作者基本信息】 温州大学 ， 物理化学， 2011， 硕士

【摘要】 本论文围绕新型铋基复合材料的制备、表征及其光催化性能等方面展开研究,内容主要包括以下三个部分:（1）通过混合溶剂热路线,在AOT参与下,于160 oC反应18 h成功合成了中空橄榄状的BiVO₄。用所得橄榄状BiVO₄为前驱体,通过热液刻蚀路线,获得了核壳结构的BiVO₄@Bi₂O₃微米球。利用X-射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、透射电镜（TEM）、BET比表面积、紫外-可见漫反射谱等分析技术对样品进行了详尽表征。系统地研究了表面活性剂、溶剂比例对产物形貌的影响。用不同时段的中间产物的X-射线衍射分析结合扫描电子显微镜像观察研究了中空橄榄状BiVO₄微米球的形成过程。光催化实验的结果显示,核壳结构的BiVO₄@Bi₂O₃复合光催化剂比单一的橄榄状BiVO₄具有更高的光催化活性。基于理论计算,分析了BiVO₄@Bi₂O₃的光催化活性增强机理。（2）以橄榄状BiVO₄为前驱体,硫代乙酰胺为硫源,在水热条件下,通过化学转化路线,合成了Bi₂S₃/BiVO₄复合光催化剂。利用X-射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、紫外-可见漫反射谱、荧光谱、EDX谱等分析技术对样品进行了表征。光催化实验的结果显示,Bi₂S₃/BiVO₄复合光催化剂比单一BiVO₄具有更高的光催化活性。当参与反应的BiVO₄和硫代乙酰胺的摩尔比为1:0.4时,产物的光催化活性最强。结合理论计算,分析了Bi₂S₃/BiVO₄复合光催化剂的光催化活性增强机理。（3）利用羧基化的碳纳米管为载体,通过水热法制备了Bi₂WO₆/CNTs复合光催化剂,利用X-射线衍射和场发射扫描电镜对产物进行表征。通过扫描电镜观察,发现反应物的浓度对最终产物的形貌有明显的影响。光催化实验的结果表明Bi₂WO₆/CNTs复合材料在可见光（λ> 400 nm）照射下对罗丹明B有良好的光催化降解作用。更多还原

【Abstract】 This paper was committed to study preparation, characterization and photocatalytic properties of bismuth-based composite materials. The main research work is listed as the following parts:（1） Hollow olive-shaped BiVO₄ microspheres was successfully synthesized in the presence of AOT under mixed solvothermal conditions at 160 oC for 18 h on a large scale. Furthermore, core-shell BiVO₄@Bi₂O₃ was obtained by thermal solution etching route, employing olive-shaped BiVO₄ as precursors. The as-obtained products were characterized by X-ray diffraction （XRD）, Field-emission scanning electron microscope （FE-SEM）, Transmission electron microscope （TEM）, BET specific surface area, and UV-vis diffuse reflectance spectroscopy in detail. The influences of surfactant and the ratios of mixed solvents on the resultant products were systematically surveyed. The formation process of hollow olive-shaped BiVO₄ was investigated through the X-ray diffraction analyses and scanning electron microscope observations of the intermediate products at the different reaction stages. The photocatalytic properties of the as-obtained hollow olive-shaped BiVO₄ and core-shell BiVO₄@Bi₂O₃ were compared. The results indicated that core-shell BiVO₄@Bi₂O₃ exhibited much higher photocatalytic activities than pure olive-shaped BiVO₄. The mechanism of enhanced photocatalytic activity of core-shell BiVO₄@Bi₂O₃ was proposed on the basis of theoretical calculation.（2） Bi₂S₃/BiVO₄ composite photocatalysts were successfully synthesized through a chemical conversion route under hydrothermal conditions, employing olive-shaped BiVO₄ as precursors and Thioacetamide （TTA） as sulfur resource. The as-obtained products were characterized by X-ray diffraction （XRD）, Field-emission scanning electron microscope （SEM）, UV-vis diffuse reflectance spectroscopy, Photoluminescence spectra and EDX spectra in detail. The photocatalytic properties of the as-obtained BiVO₄ and Bi₂S₃/BiVO₄ composite photocatalysts were compared. The results indicated that Bi₂S₃/BiVO₄ composite photocatalysts exhibited much higher photocatalytic activities than pure BiVO₄. It was found that Bi₂S₃/BiVO₄ composite semiconductor prepared with molar ratio of BiVO₄: TAA=1:0.4 shows the best photocatalytic acticity. Combined with theoretical calculation of band-edge positions of the two semiconductors, the mechanism of enhanced photocatalytic activity of Bi₂S₃/BiVO₄ was proposed.（3） Bi₂WO₆/CNTs composite photocatalysts were synthesized under hydrothermal conditions, using carboxylated carbon nanotubes as supports. The as-obtained products were characterized by X-ray diffraction （XRD） and Field-emission scanning electron microscope （FE-SEM） in detail. The influence of the concentration of reactants on the morphology of resultant products was studied by field-emission scanning electron microscope. The photocatalytic results shows Bi₂WO₆/CNTs nanocomposite materials have good photocatalytic performance on the degradation of Rhodamine B under visible-light irradiation （λ>400nm）.更多还原