【作者】 田皓；

【导师】 李怀祥；

【作者基本信息】 山东师范大学 ， 物理化学， 2010， 硕士

【摘要】 1972年,日本学者藤岛昭和本多健一在n型半导体TiO₂电极上发现了水的光电催化分解作用。以此为契机,开始了多相催化研究的新纪元。半导体光催化氧化技术是一种新型的现代水处理技术,由于它能广泛地利用天然能源-太阳能,且对多种有机物有明显的降解效果,因此具有广阔的应用前景。但是以TiO₂为典型代表的光催化剂在传统方法上的应用存在着量子效率低以及回收困难等缺点而限制其工业化的推广应用,因此国内外学者积极展开了对这方面的系统研究,其中包括TiO₂催化剂的表面修饰、固载、重金属沉积、复合半导体、掺杂稀土元素等技术。本课题旨在开展对二氧化钛与杭锦2^#土的复合条件以及光催化降解亚甲基蓝的研究,探索其最佳制备工艺条件及降解有机物的一般规律,以期进一步充实光催化剂的负载技术以及有机污水治理方面的研究,为光催化剂的工业化推广运用补充血液。本论文主要由以下六部分组成:第一部分:系统回顾了光催化材料的发展状况及优点,全面阐述了纳米TiO₂光催化技术在应用、改性、制备、载体等方面的研究情况。第二部分:将原杭锦2^#土经过杭锦2^#土的前处理、杭锦2^#土的活化、水洗分酸、干燥粉碎四个步骤制成活性白土。通过XRD和FTIR对样品进行了表征。第三部分:以钛酸丁酯和活化土为原料,采用溶胶-凝胶法制备了一系列TiO₂/杭锦2^#土复合光催化剂。用XRD、FTIR、BET、SEM、XPS和TG等分析方法对复合光催化剂的物相组成、晶相等物化性质进行了表征。第四部分:采用溶胶-凝胶法掺杂LiF和Sr分别制备了LiF-TiO₂/杭锦2^#土和Sr-TiO₂/杭锦2^#土复合光催化剂。用XRD和FTIR对催化剂进行了表征。第五部分:以亚甲基蓝水溶液为光降解体系,在紫外光照射下,利用不同条件下制备的样品作为光催化剂进行光催化降解,考察了不同制备条件下的样品的光催化性能,并探索出复合光催化剂的最佳制备条件。第六部分:结论及展望。更多还原

【Abstract】 Since A. Fujishima and K. Honda first reported the photosensitized decomposition of water into hydrogen and oxygen by titanium dioxide （TiO₂） electrode in 1972, a lot of research works have focused on understanding the fundamental processes and on enhancing the photocatalytic efficiency of semiconductor catalysts. The technique of photocatalytic oxidation which utilizes a semiconductor as a catalyst is a new kind of water treatment process with great potential application in water treatment for its good ability to utilize natural resource-solar energy and its outstanding effect on degradation of organic substances.However, the use of conventional photocatalyst that is typically delegated by titanium dioxide results in disadvantages of low quanta efficiency and of separation after the reaction, which confined the industrial application. And different methods including surface modification of TiO₂, support, deposition of heavy metals, the compound semiconductors, the rare elements mixed into TiO₂ were studied abroad and at home.The aim of this dissertation is to initiate the research of the synthesis conditions of titanium dioxide based on Hangjin 2^# clay and the degradation of methylene blue （MB） aqueous solution in order to seek optimal condition and general degradation rules, by which we look forward to building up the base for further research.This thesis mainly consists of six major parts:Part 1: This part systemically reviewed the development and the advantages of the photochemical catalysis material. The application, modification, preparation and carrier research situation of the nanometer TiO₂ photochemical catalysis technology are described in detail.Part 2: After pre-treatment, acid activation, washing and dehydration, Hangjin 2^# clay changed into activated clay. Then the samples were characterized by XRD and FTIR.Part 3: A series of TiO₂ /Hangjin 2^# clay compounds were successfully synthesized by a sol-gel process using Ti （OC4H9）4 and activated clay as raw materials. The composite catalysts were characterized by means of XRD, FTIR, BET, SEM, XPS and TG.Part 4: TiO₂/Hangjin 2^# clay composites have been doped by lithium fluoride （LiF） and strontium （Sr） via sol-gel method. X-ray diffraction （XRD） and Fourier transformed infrared （FT-IR） spectroscopy were used to characterize composites.Part 5: The photocatalytic characteristics of composites were evaluated by measuring decomposition of methylene blue in aqueous solution under UV irradiation.Part 6: Conclusion and prospect.更多还原