【作者】 张扬；

【导师】 柳丽芬；

【作者基本信息】 大连理工大学 ， 环境工程， 2006， 硕士

【摘要】 纳米TiO₂因具有高活性、安全无毒、化学性质稳定（耐化学及光腐蚀）、难溶于酸和碱、成本低等优点，其应用前景极好，成为人们研究的热点。当前，人们利用纳米TiO₂光催化降解有机污染物的研究已经相当多，而且近来对无机污染物的光催化处理研究也日益增多。水中无机氮主要指氨氮、亚硝态氮和硝态氮。排放水体的氨氮、亚硝酸氮和硝态氮是危害较大的环境污染物，主要来源于工业废水、生活污水和农业灌溉废水。本研究以无机氮作为目标污染物，利用溶胶-凝胶法制备的掺杂金属离子的纳米TiO₂和耦合光催化氧化还原反应来脱除水中无机氮作为研究的主要内容。通过X射线衍射（XRD）、透射电镜（TEM）、紫外-可见吸收光谱（UV-VIS）、X光电子能谱（XPS）分析手段对催化剂进行了表征，并考察了催化剂光催化脱除水中无机氮的活性及主要影响因素。 （1）制备了掺杂Ce³⁺、La³⁺、(Ce³⁺+Ag⁺)的TiO₂薄膜光催化剂，XRD、TEM分析得知，催化剂为锐钛矿型，催化剂的平均粒径约为10nm。利用催化剂进行对模拟含氮污水光催化脱氮研究。对影响TiO₂光催化效率的因素：如掺杂金属离子的种类、浓度、涂膜层数、反应液中有无Fe²⁺、不锈钢和玻璃载体、反应器的构型等进行了考察。经过2小时紫外光照射反应，金属离子掺杂TiO₂薄膜型催化剂最佳脱氮效果的总氮去除率在30％左右。 （2）制备了Ce³⁺和Ag⁺共掺杂的TiO₂粉末催化剂。XRD、TEM分析催化剂为锐钛矿型，催化剂的平均粒径约为10nm，XPS分析表明，由于掺杂，钛的2p轨道结合能有所下降。对模拟含氮污水进行光催化脱氮研究。考察了影响TiO₂光催化效率的几个主要因素：共掺杂各金属离子的浓度、反应液比例、制孔剂的种类及加入量、不同光源等，并对影响脱氮效果原因进行了探讨。利用(0.1％Ce³⁺+0.1％Ag⁺)／TiO₂催化剂，经过2小时的光照反应，获得了最佳脱氮效果：可去除69.9％氨氮，同时去除59.9％亚硝酸氮，总氮去除率达64.9％。更多还原

【Abstract】 The nanometer TiO₂ has been the focus of photocatalyst studies because of its non-poisonous feature high activity, security, stability（able to bear chemical corrosion, did not dissolve in the acid alkali conditions）, low cost and other advantages.The application prospect is extremely good. At present, the nanometer TiO₂ is often used as a catalyst for the organic pollution. Recently the nanometer TiO₂ is also used as a catalyst for the inorganic pollution control. The inorganic nitrogen in the water contains ammonium nitrogen, nitrite nitrogen and nitrate nitrogen. Ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the water are the main environmental pollutants from industrial, domestic and agricultural waste waters, also from landfilling leachates, aminal farms. This research aimed at removal of inorganic nitrogen （the target pollutant） from water using photocatalysis and metal ion doped nano- TiO₂, that were prepared by a sol-gel method. It is realized via coupled ammonia oxidation and nitrite reduction, which is the main content of this study. The photocatalysts were characterized with XRD, TEM, UV-VIS, XPS, the influences of several key factors for nitrogen removal were investigated.（1） TiO₂ thin film photo-catalysts doped with Ce³⁺ La³⁺, (Ce³⁺+Ag⁺) were prepared. The results of XRD and TEM showed that the crystal structure of catalysts were of anatase type, and the average size of TiO₂ particles was about 10nm. The oxidation and reduction capability of the thin film have been studied comprehensively from some important factors of the photo-catalytic nitrogen removal in the reaction, such as different kinds and concentration of doped metal ions, dipping times（thickness of catalyst films）, addition of Fe²⁺to the solution, different substrate （glass or stainless steel mesh）, different designs of reactor and different light sources （UV or solar light） on photo-catalytic N removal efficiency. After 2 hours UV irradiation, simultaneous removal of ammonium and nitrite could be achieved. The removal efficiency for TN was about 30% when TiO₂ film was used.（2） TiO₂ photo-catalysts co-doped with Ce³⁺ and Ag⁺ were prepared. The results of XRD and TEM showed that the crystal structure of catalysts were of anatase type, and the average size of TiO₂ particles was 10nm. XPS spectra indicated the effect of doped ions on the binding energy of Titanium. The oxidation and reduction capability of the thin film have been studied更多还原