【作者】 吕博；

【导师】 杨胜科；

【作者基本信息】 长安大学 ， 环境科学， 2007， 硕士

【摘要】 TiO₂光催化材料由于其催化降解有机物的效果良好,而且性能稳定、无毒,成为近20年来水环境污染治理技术研究的热点之一。但传统的TiO₂光催化材料不易回收、浪费严重、运行成本较高,使该技术至今未能大规模应用于降解处理有机废水。本文以探索一种既高效降解又便于回收、可重复利用的光催化材料为目标进行研究。在查阅大量文献资料的基础上,拟定实验方案如下:以纳米Fe₃O₄为基材粒子,于其上包覆TiO₂光催化材料,使其具备磁性,便于回收。鉴于磁性TiO₂光催化材料降解率低的问题,采用膜包覆技术,选用Al2O₃、SnO₂、SiO₂对磁性光催化材料进行复合改性,并探讨了制备条件对其光解性能的影响,研究获得:（1）选取自制TiO₂与商品TiO₂进行光催化性能对比实验。结果表明,催化光解160min后,降解率分别为94%、99%,认为自制TiO₂光催化材料可行,为在实验室条件下对自制TiO₂的复合改性奠定基础。（2）以滴定水解法制备Fe₃O₄磁核对自制TiO₂光催化材料负磁,并验证其磁性能。结果表明,该材料具备了优良的磁性能,能够通过磁性分离技术有效回收,但其光解160min后,降解率仅为32.68%,反映光催化降解性能较低。（3）为了提高磁性光催化材料的降解效率,分别选用Al2O₃、SnO₂、SiO₂对其复合改性。光解160min后,Al2O₃复合磁性光催化材料具备了最好的催化降解效果,降解率为93.28%,SnO₂、SiO₂复合磁性光催化材料的降解率分别为86.0496和79.63%。（4）用Al2O₃复合的磁性光催化材料连续六次处理相同浓度的亚甲基兰溶液,第两次、第三次重复使用时的降解率分别为新催化材料的93.91%、85.44%。此后催化降解效果迅速下降,在重复使用五次后,仅为59.77%。（5）通过对Al2O₃复合磁性光催化材料扫描电镜（SEM）表观形貌及其材料吸附性实验的研究,得出该材料催化性能的提高与Al2O₃的加入改变其吸附性能有关。（6）Al₂O₃复合磁性光催化材料光催化降解亚甲基兰反应,符合一级反应动力学方程,ln（Co/C）与时间t保持了良好的线型关系。Al2O₃复合磁性光催化材料的成功合成,可望为光催化剂的回收和推广利用提供新的途径。更多还原

【Abstract】 As a traditional environment-purifying technique,photocatalysis degradation has been widely researched in the domain of environment pollution.But until now,it has not been used in the industrialized water pollution control.Two factors weigh heavily against it.First,the powder recycling is very difficult.Second,the cost of photocatalysis degradation is still low. Basing on all of it,this article take focus on produce a new photocatalyst that can resolve these problems.In order to recycle the photocatalyst,synthesiseing a magnetic photocatalyst by direct deposition of TiO₂ onto a magnetic core.Relying on the success above,pick Al₂O₃,SnO₂, SiO₂ as composite materials,produce Al₂O₃/Fe₃O₄/TiO₂、SnO₂/Fe₃O₄/TiO₂、SiO₂/Fe₃O₄/TiO₂ magnetic composite photocatalyst and investigate capability all of these.The results are summarized as following:（1） The TiO₂ photocatalyst which have been produced in lab have a great effect of photocatalysis degradation.（2） The magnetism of Fe₃O₄/TiO₂ is excellent.The material of Fe₃O₄ and TiO₂ get well integrated,but the degradation rate of is low.（3） All of the three magnetic composite photocatalyst have better effect of photocatalysis degradation compare with Fe₃O₄/TiO₂,their photocatalytic activity could arrange like this: Al₂O₃/Fe₃O₄/TiO₂> SnO₂/Fe₃O₄/TiO₂> Si_O2/Fe₃O₄/TiO₂,the degradation rates are 93.28 %,86.04%,79.63%.（5） The reason why Al₂O₃/Fe₃O₄/TiO₂ could get a better photocatalytic activity is that going with the Al₂O₃ entered.The magnetic composite photocatalyst could get a better adsorption behavior.（6） Repeating use Al₂O₃/Fe₃O₄/TiO₂ with 6 times.The second and third one could get much better degradation rate compare with the following ones.（7） The photodegradation experiment is in accordance with langmiur-hisheshood formula.更多还原