【作者】 陈杰博；

【导师】 林深；

【作者基本信息】 福建师范大学 ， 物理化学， 2008， 硕士

【摘要】 染料废水是主要有害的工业废水之一,具有成分复杂、色度高、可生化性差等特点,是废水处理中的难题。光催化氧化技术在处理染料废水上是一个具有良好应用前景的研究课题,它具有高效、节能、无二次污染、适用范围广等优点,因而引起了广大学者的关注。而光催化技术的核心是光催化剂的合成及应用,制备高效的可见光响应的光催化剂成为了化学和环境科学科研工作者的中心任务。本研究以PAMAM为模板制备了介孔钨酸锌、钨酸钴、N掺杂钨酸锌及ZnS/CdS固熔体,通过X射线衍射（XRD）、透射电镜（TEM）、固体紫外漫反射（DRS）、X光电子能谱（XPS）分析手段进行结构表征,以印染废水为目标污染物,在紫外或可见光条件下,考察了催化剂的合成条件和光催化反应条件对光催化降解染料废水反应活性的影响。结果表明:介孔ZnWO₄光催化剂在紫外光照射下,40min即可使罗丹明B和孔雀石绿两种染料完全褪色,照射80min后,染料结构完全被破坏。COWO₄光催化剂,在可见光光照3h后,能使3.2×10^-5M的亚甲基蓝（MB）的褪色率达到了90%以上,并且催化剂性能稳定。经过N掺杂改性后的ZnWO₄光催化剂在不但在可见光下具有光催化性能,而且同时保持了紫外光催化活性。同时本论文以PAMAM模板,采用共沉淀法开发了纳米复合Cd_1-xZn_xS光催化剂,可见光光照100min后,95.1%的罗丹明被降解,其光催化反应机理进一步的进行讨论,复合物能有效的阻碍电子和空穴的复合。更多还原

【Abstract】 Dye wastewater is an important source of harmful industry wastewater. The composites of dye wastewater are very complicated, toxic and mostly nonbiodegradable. Photocatalytic oxidation technology is one of important methods used for dye treatment, which has a lot of advantages, such as high efficiency, energy saving, no second contamination and so on. The synthesis and application of photocatalyst is the key of photocatalytic oxidation technology, and the researchers have being searching new photocatalysts with high-activity. In this thesis, ZnWO₄, COWO₄, N doped ZnWO₄ and ZnS/CdS photocatalysts were prepared with the template of PAMAM. The photocatalytic degradation of dye（RhB, MB and MG） in aqueous solution is used as a probe to evaluate their photocatalytic activities. XRD, XPS, HRTEM, SEM, BET, FTIR, nitrogen adsorption-desorption were used to characterize their structures and properties. The influences of several key factors for dye removal were investigated. The results show that mesoporous ZnWO₄ can photodegrade rhodamine B （RhB） and malachite green （MG） under UV light. To efficiently utilize solar energy, nanosized CoWO₄ has been prepared with the template of PAMAM. Visible-light-induced photodegradation of methylene blue （MB） over CoWO₄ exhibited high photoactivity, the recycles for photodegradation of methylene blue exhibit that the photocatalyst is essentially stable. N-doped ZnWO₄ was prepared by the template of PAMAM. The photocatalytic activities of N-doped ZnWO₄ on degradation of RhB were evaluated under visible light and UV irradiation, the result show that N-doping play a major role on improving the photocatalytic avtivity. Meanwhile, Cd_1-xZn_xS solid solution was prepared by coprecipitation method with PAMAM as a template, The results indicated that Cdo.59Zno.22S solid solution exhibited the highest photocatalytic activity among all the as-prepared samples. The mechanism of Photocatalysis under visible light irradiation was also discussed.更多还原