【作者】 李媛媛；

【导师】 倪刚；

【作者基本信息】 宁夏大学 ， 应用化学， 2014， 硕士

【摘要】 随着工业的发展,全球环境问题日益加重。工业废水是我们所面临的主要问题,电镀、冶金、印染等废水排放到自然环境中会造成很严重的污染。而印染废水具有水量大、碱性大、有机污染物含量较高、水质变化大等特点,属较难处理的工业废水之一。因此寻找一种合适的催化剂至关重要,二氧化钛是目前备受关注的催化剂,它有着化学性质稳定、制备简便、成本低、不溶于水等优点,是一种比较理想的催化剂。但一般实验室制备出的二氧化钛存在颗粒分布不均匀、分散性较差易团聚,而且二氧化钛是一种半导体氧化物,电子与空穴容易复合,选择性较低,这些缺点都会导致二氧化钛的催化效率降低。为了解决上述问题,本论文将从以下实验内容进行研究：1、以钛酸四丁酯为前驱体,无水乙醇做溶剂,冰醋酸做抑制剂,盐酸做负催化剂,采用溶胶-凝胶法制备纳米二氧化钛。正交试验分析研究了溶剂量,加水量,抑制剂量,凝胶温度,搅拌速率等对二氧化钛溶胶-凝胶形成过程以及凝胶时间的影响,总结出了制备稳定溶胶的制备工艺及影响二氧化钛光催化性能的主要因素。并对其结构和形貌进行XRD、SEM表征。2、以硫脲为硫源,硫酸锌为锌源,采用改性的溶胶凝胶法制备出了高活性的S-TiO2、Zn-TiO2、Zn-S-TiO2光催化剂,利用甲基橙为反应模型,研究不同掺杂量对光催化性能的影响,对其进行光催化效果评价。采用傅利叶红外光谱、X射线衍射、紫外可见漫反射、X荧光光谱等手段对其进行表征。结果表明：所得样品均为锐钛矿相二氧化钛,掺杂后的催化剂吸收强度有了明显的增强,吸收谱带发生了较明显的红移,表明了掺杂Zn和S能使Ti02中形成了掺杂能级。掺杂后的光催化剂催化活性也有了明显提高。3、以硫脲为硫源,硫酸锌为锌源,粉煤灰和硅灰分别为载体,采用溶胶凝胶法制备了掺杂负载型光催化剂,以甲基橙为反应模型,研究了不同掺杂量、不同负载量对光催化性能的影响,对其进行光催化效果评价。采用傅利叶红外光谱、X射线衍射、扫描电镜、透射电镜等手段对其进行表征。结果表明：粉煤灰或硅灰的负载能减少二氧化钛的团聚现象,改善其颗粒的分布情况,提高其光催化性能。负载型催化剂出现载体的特征衍射峰,说明TiO2成功负载到两种载体上。掺杂负载型催化剂催化活性高于掺杂型催化剂。4、以中性红为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用表面聚合的方法制备了分子印迹聚合物,采用正交实验确定模板分子、功能单体和交联剂之间的最佳摩尔比为1：4：20时,降解率最高。印迹型催化剂具有较明显的选择催化效应,在降解目标分子底物时,表现出了比非印迹催化剂更高的催化活性。而在降解非目标分子底物时,印迹型催化剂没有选择催化降解效应,催化活性与非印迹催化剂相似。更多还原

【Abstract】 With the development of the industry, the global environmental problems have become more and more serious. Industrial wastewater is the main problem we are facing, especially the electroplating, metallurgy, printing and dyeing wastewater. They will cause serious pollution once they are poured into the environment. What’s more, dyeing wastewater is one of the most difficult wastewater to deal with because of its characteristics of rich water, thick alkali, high content of organic pollutants and changeable water quality. So, it is really important to search for a kind of suitable catalyst. TiO2is an ideal catalyst with its advantages of chemical stability, easy making, low cost and insoluble in water. However, the TiO2produced by general chemical experiments has poor efficiency of catalytic and low selectivity, for its poor distribution and easy reunion. Besides, TiO2is a kind of semiconductor oxide, electrons and holes are easy to compound. Therefore, to solve these problems, the paper will study from the following chemical experiments.1、The nano-TiO2photocatalytic materials were prepared by Sol-gel method with Ti(OC4H9)4as the main raw material, C2H5(OH) as solvent, CH3COOH as inhibitor, HCl as anti-catalyst. The effects of solvent amount, water amount, inhibitory dose, gel temperature, stirring rate on the sol-gel process and gel time of TiO2were studied by orthogonal test, and synthetic process of stable sol and main factors of performance of nano-TiO2photocatalytic materials were summarized.The structure and morphology of the obtained samples were characterized by X-ray diffraction, scanning electron microscope.2、Using thiourea dioxide as sulfur source, zinc sulfate heptahydrate as zinc source,sulfur-doped titania photocatalyst,zinc-doped titania photocatalyst and sulfur-zinc-doped titania photocatalyst were prepared by sol-gel method. The photocatalytic activity of the samples was tested for degradation of methyl orange (MO) solutions. Researched the effect of photocatalytic activities by the different doping amounts.The samples had been characterized by infrared spectroscopy(IR), X-ray diffraction(XRD), diffuse reflectance ultraviolet visible(DRUV), X-fluorescence spectra(XRF). The results showed that photocatalytic activity of the doped TiO2was improved significantly,the co-doped catalyst shave anatase phase and the absorption intensity was enhanced obviously, the absorption edges of it shifted to visible light region,indicates that the N, S-codoped nanosize TiO2,was formed of a new impurity level.3、The Zn-S-TiO2/fly ash and Zn-S-TiO2/silica fume photocatalysts were prepared using sol-gel technique in this work. The photocatalytic activity of the samples was tested for degradation of methyl orange (MO) solutions. Researched the different doping amount and different loading capacity the effect of photocatalytic activities. The samples had been characterized by infrared spectroscopy(IR), X-ray diffraction(XRD), scanning electron microscope(SEM), transmission electron microscope(TEM). The results showed that the photocatalytic activity of doped-load type catalyst is higher than the doped catalysts.The possible reason is that the load of fly ash or silica fume can decrease the reunion phenomenon of TiO2, improve the distribution of the particles, improve the photocatalytic performance.The load type catalyst appear characteristic diffraction peaks of carrier.It is prove that TiO2is loaded on the two carriers successfully. 4、Neutralred moleculary inmrinted polymers were prepared by Surface polymerization method using neutral red as templat, methacrylicas as functional monomer,ethylene glycol dimethacrylate as cross-linker, The effects of template, functional monomer and cross-linker were studied by orthogonal test,the best molar ratio is1:4:20,the degradation rate is the highest.The NE-imprinted TiO2catalyst,imprinted catalyst exhibited a selective catalytic activity for the photo-catalyzed degradation of target-substrate molecules.When degrading non-target-substarate molecules,the NE-imprinted TiO2catalysted a similar activity with the non-imprinted catalyst.更多还原