｛111｝晶面暴露纳米金红石二氧化钛的制备及光催化研究

发布时间：2018-03-23 17:02

本文选题：金红石二氧化钛　切入点：纳米　出处：《杭州电子科技大学》2015年硕士论文

【摘要】：过去的几十年年中,随着科技的持续发展,人们对环境资源等也带来了破坏,水污染问题日趋严重反复引起公众关注。环境以及能源等问题显然以及成为21世纪的首要解决的重大问题之一。而近年来光催化技术逐渐被人们重视,光催化指的是半导体在一定波长的光照下,发生载流子的分离同时产生光生电子以及空穴并且和溶液中的离子生成含有氧化性或者还原性的活性自由基,这些物质能够很有效的将水中的很多有机物降解成为二氧化钛和水等物质,这样就起到了污水处理为作用。由于光催化的方法非常环保无二次污染,且效率很高,成为当下环境治理问题的新方向。而选择性光催化是光催化剂的特性之一,也是研究的的难点之一,因其既可以对于普通情况的污染物进行降解同时也具备了污染物的选择性降解的特点,对于这方面的研究并不是很多。所以对如何利用纳米二氧化钛进行高效的光催化以及探究其在选择性方面的特点具有很高的研究价值。由于二氧化钛是过渡金属氧化物且无毒无害并且催化效率很高,化学稳定性好是一种理想的光催化材料。本文的研究主要是围绕金红石型纳米二氧化钛的制备和其光催化性能和选择性光催化的性能的研究展开的。在二氧化钛的三种形态中锐钛矿和金红石的催化性能较好,而对金红石的研究比较少,尤其是对于{111}暴露面金红石纳米二氧化钛的研究更为稀少,本课题采用了水热法通过钛酸四丁酯Ti(OBu)4混合Na F,HCl的方法制备得到了{111}暴露面的金红石型二氧化钛。并对其进行了XRD以及SEM,TEM,HRTEM等一系列表征方式,对催化剂的形貌结构和晶体结构的研究。并且对其进行了选择性光催化甲基橙和亚甲基蓝以及甲基橙和甲基紫的研究,记录催化过程并且通过紫外分光光度计对其催化结果进行分析。本课题研究得到了一些新的结果:我们利用水热法制备得到了一种高纯度的{111}暴露面金红石纳米二氧化钛,在不断调节使得其Cl-和F-是最佳浓度比例的时候获得了大约为96%左右的{111}暴露面金红石型的纳米二氧化钛。经过试验验证了其光催化的活性是{110}暴露面的金红石的三倍左右,有着比较高的光催化效率。确定了它的确有着更高的光催化性能相比{110}暴露面的金红石而言。而最关键的高光催化性能的因素可能是{111}暴露面中含有更多的不饱和O2c。同我们对其的选择性光催化的特性也做了研究,实验结果表明,金红石纳米二氧化钛对于甲基橙和亚甲基蓝的选择性较弱,但是在甲基橙和甲基紫之间表现出较强的选择性,优先降解甲基紫。
[Abstract]:In the last few decades, with the continuous development of science and technology, people have also caused damage to the environment and resources. The problem of water pollution is becoming more and more serious. The problems of environment and energy are obviously one of the most important problems to be solved in the 21st century. In recent years, photocatalytic technology has been paid more and more attention. Photocatalysis refers to the separation of carriers in semiconductors at certain wavelengths of light to produce photogenerated electrons and holes and to form active free radicals containing oxidizing or reductive properties with ions in the solution. These substances can effectively degrade a lot of organic matter in the water into titanium dioxide and water and so on, and thus play a role in sewage treatment. Because the photocatalytic method is very environmentally friendly, no secondary pollution, and high efficiency, Selective photocatalysis is one of the characteristics of photocatalyst, and it is also one of the difficulties in research. Because it can not only degrade pollutants in ordinary conditions, but also have the characteristics of selective degradation of pollutants, Therefore, it is of great value to study how to use nano-TiO _ 2 as a highly efficient photocatalyst and to explore its characteristics in selectivity. Because titanium dioxide is a transition metal, it is a transition metal. The oxide is nontoxic and harmless, and the catalytic efficiency is very high. Chemical stability is an ideal photocatalytic material. This paper focuses on the preparation, photocatalytic and selective photocatalytic properties of rutile nano-TiO _ 2. Anatase and rutile have better catalytic performance. However, there are few studies on rutile, especially on {111} exposed rutile nano-TiO _ 2. In this paper, rutile titania with {111} exposed surface was prepared by hydrothermal method using tetrabutyl titanate Ti(OBu)4 mixed with Na FG HCl. It was characterized by XRD and SEMTEMHRTEM. The morphology and crystal structure of the catalyst were studied, and the selective photocatalysis of methyl orange and methylene blue and methyl orange and methyl violet were carried out. The catalytic process was recorded and the catalytic results were analyzed by UV spectrophotometer. In this paper, some new results were obtained: we prepared a high purity {111} exposed rutile nano-TiO _ 2 by hydrothermal method. About 96% of {111} exposed rutile nanocrystalline titania was obtained when the ratio of Cl- and F- was adjusted continuously. The photocatalytic activity of {111} exposed rutile was about three times as high as that of {110} exposed rutile. It is determined that it does have higher photocatalytic performance than rutile with {110} exposed surface. The most critical factor of photocatalytic activity may be that the {111} exposed surface contains more undersaturation. And O2c. have also done research with us on their selective photocatalytic properties, The experimental results show that the selectivity of rutile nano titanium dioxide to methyl orange and methylene blue is weak, but the selectivity between methyl orange and methyl violet is strong, and the degradation of methyl violet is preferred.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ134.11;O643.36

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