导　　师： 刘国光

学科专业： 081704

授予学位： 博士

作　　者： ;

机构地区： 广东工业大学

摘　　要： Ti0：光催化技术是目前被广泛关注的一项催化新技术。Ti0：在受光照后会产生电子-空穴对,光生电子具有很强的还原能力,光生空穴具有很强的氧化能力,当污染物种/(如有机物或金属离子/)吸附到半导体Ti02表面时,就会分别得到电子或空穴,发生相应的氧化还原反应。利用电子-空穴的协同作用,同时去除环境中的氧化态和还原态的污染物成为当前催化和环境保护研究领域的一个研究热点。本课题在以下几个方面做了一些研究工作,为开拓TiO2纳米管催化剂在同步处理有毒有机废水和含重金属离子的废水方面提供了理论基础。1.以纳米Ti02为原料,采用水热合成法制得Ti0：纳米管。采用红外光谱/(FT-IR/)分析、X衍射/(XRD/)分析和电镜扫描分析进行表征。表明用水热合成法制备的纳米管不会改变其晶型,同样主要为锐钛矿型,含有少量金红石型；相比纳米Ti02,制得的Ti02纳米管晶粒尺寸较小,增大了比表面积和孔体积、具有相对较好的分散性能,克服了纳米Ti02颗粒容易团聚的现象,制备出来的Ti0：纳米管在理论上具有良好的光催化活性。2.在总体积为500 mL、反应物浓度为2×10-mol//L、300W紫外光照射下/(体系中的光密度为8 MW//cm2/)、温度控制在26±0.5℃、空气曝气/(300 mL//min/)、TiO2纳米管的浓度为2.0 g//L实验条件下,用所制备的TiO2纳米管进行光催化降解EDTA、酒石酸、柠檬酸和DTPA的研究。实验发现尽管紫外光也能直接光解EDTA.酒石酸、柠檬酸和DTPA,但Tj0：纳米管的加入,可以促进四种有机物的降解,使反应速率更快,反应更彻底。1小时后,采用高效液相色谱/(HPLC/)很难检测到体系中的有机物。表明Ti02纳米管光催化法非常适合于含EDTA、柠檬酸、酒石酸和DTPA废水的处理。3.用所制备的Ti02纳米管进行光催化还原Cu/(Ⅱ/)和Ag/(Ⅰ/)的实验。1小时后Cu/(Ⅱ/)和Ag/(Ⅰ/)的去除率分别达� Recently, it has been demonstrated that photocatalysis is a promising technology applicable for the treatment of pollutants. Electron-hole pairs will be consistently generated from semiconducting TiO2 under irradiation, with electron'strong reducing power and the holes'strong oxidizing power, when electron-hole pairs are trapped by the contaminant /(e.g., organic pollutants and//or metal ions/) on surface, redox reactions will be initiated. Thus, the electron-hole synergy has been used to remove pollutants of oxidation and reduction state of the environment synchronously, becoming a hot topic in catalytic and environmental research. We have done some research work in the following areas, which provides a theoretical basis for the development of using TiO2 nanotubes photocatalysis to remove synchronously toxic organics and heavy metal ions in the wastewater.TiO2 nanotube was successfully synthesized by a hydrothermal method. The TiO2 nanotube photocatalytic material were characterized by using FT-IR spectrum, scanning electron microscope, X-Ray diffraction and BET surface area analysis etc. The results showed that the TiO2 nanotubes prepared by hydrothermal synthesis method are also primarily anatase and contain a small amount of rutile, not changing its crystal form. Compared to nano-TiO2, TiO2 nanotube grain sizes are smaller, while its surface area and pore volume are larger. Furthermore, TiO2 nanotubes are relatively good dispersion properties and can't easily reunion, which proves to prossess excellent photocatalytic activity.The experiments were carried out under the following conditions:magnetic stirrer; initial concentration.2×10-5mol//L; temperature, fixed at 26±0.5℃; TiO2 nanotubes concentration,2.0 g//L; the suspensions 500 mL; aerated at a flow rate of 300 mL//min; the average light intensity, about 8 MW//cm2; under 300W ultraviolet light irradiation. The persent study is targeted on using TiO2 nanotubes photocatalytic degradation of EDTA, citric acid, tartaric acid and DTPA. It was found that the

关 键 词： 纳米管 光催化 同步去除 重金属 有机物 协同作用与机理

领　　域： [环境科学与工程]