钴掺杂二氧化钛纳米管的制备及光催化性能研究

发布时间：2018-03-17 20:49

  本文选题：钴掺杂　切入点：二氧化钛　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着工业的发展，人们的生活水平有了显著提高，然而，这是以环境污染和能源危机的日益加剧为代价的。因此找到如何使用先进的科学技术来解决环境和能源问题的办法是十分重要的。纳米材料光催化剂能够在室温下利用太阳能促使化学反应的发生，因此利用它来治理环境污染以及生产清洁能源的技术研发工作具有十分深远的意义。目前，纳米光催化技术在环保、化工、医药、食品等领域都发挥着重要的作用，但仍然存在着一些问题。如何在当代科技领域有效地应用这种技术已然成为了当代科学中主要的研究热点之一。 （1）TiO2光催化活性不高，对可见光的利用还有待开发，人们对如何提高TiO2的光催化活性，开发高效光催化剂还需要做进一步的研究。 （2）半导体光催化氧化活性的关键在于电子-空穴对的复合与电荷转移，因此我们对如何捕获电子，减少电子-空穴对的复合的几率要做更深入的研究。 （3） TiO2的制备方法和改性方法还可以优化，制备出光催化性能更好的TiO2光催化材料。 本论文研究的主要内容是： 一、利用共沉淀法和水热煅烧法制备出TiO2纳米管，研究水热反应中NaOH浓度对TiO_2纳米管光催化性能的影响，通过单因素实验和正交试验研究水热反应温度、水热反应时间、煅烧温度、煅烧时间对TiO2光催化性能的影响，从而确定最佳工艺参数。 二、利用前面所得到的最佳反应条件制备不同钴离子掺杂量的二氧化钛，对所得到的样品通过X射线衍射（XRD）和透射电镜（TEM）分析样品的晶体晶型和内部结构，通过EDS对样品进行元素分析。以亚甲基蓝作为目标降解物研究不同钴离子掺杂量对样品光催化性能的影响，从而得到钴离子最佳掺杂量，使该样品对亚甲基蓝的降解率最高。 三、研究光催化过程中光源，亚甲基蓝初始浓度，光催化剂加入量对光催化反应的影响。 实验结果表明：当水热反应碱液浓度为10mol/L、水热反应温度为130℃、水热反应时间为36h、煅烧温度为400℃、煅烧时间为3h时，所得的二氧化钛对亚甲基蓝的降解率最高，可以达到81.3%。当钴离子掺杂量为1.3%时，所得到的Co-TiO2催化率最高，为97.2%。实验结果表明钴离子掺杂促进二氧化钛光催化反应，钴离子掺杂1.3%的二氧化钛较未掺杂的样品光催化活性提高15.9%。另外对钴离子掺杂1.3%的二氧化钛样品和纯二氧化钛样品进行XRD、TEM、EDS等表征分析。XRD结果表明最佳工艺参数下制备出的钛氧化物为锐钛矿相。TEM结果表明，最佳工艺参数下制备出的钛氧化物为纳米管结构，管长为50-100nm，管径为15nm左右。EDS分析表明钴离子掺杂在二氧化钛晶格中。亚甲基蓝初始浓度为20mg/L，光催化剂加入量为20mg。
[Abstract]:With the development of industry, people's living standard has been improved significantly, however, This is at the expense of environmental pollution and the growing energy crisis. It is therefore important to find ways to use advanced science and technology to solve environmental and energy problems. Nanomaterials photocatalysts can be used at room temperature. Using solar energy to promote chemical reactions, Therefore, it is of great significance to use it to control environmental pollution and produce clean energy technology. At present, nanometer photocatalytic technology plays an important role in the fields of environmental protection, chemical industry, medicine, food and so on. However, there are still some problems. How to effectively apply this technology in the field of contemporary science and technology has become one of the main research hotspots in contemporary science. The photocatalytic activity of TiO2 is not high and the utilization of visible light is still to be developed. It is necessary to do further research on how to improve the photocatalytic activity of TiO2 and how to develop high efficient photocatalyst. 2) the key to photocatalytic oxidation of semiconductors lies in the recombination and charge transfer of electron-hole pairs, so we need to do more in-depth research on how to capture electrons and reduce the probability of recombination of electron-hole pairs. The preparation and modification methods of TiO2 can also be optimized to prepare TiO2 photocatalytic materials with better photocatalytic performance. The main contents of this thesis are as follows:. Firstly, TiO2 nanotubes were prepared by co-precipitation and hydrothermal calcination. The effects of NaOH concentration on photocatalytic properties of TiO_2 nanotubes were studied. The hydrothermal reaction temperature and hydrothermal reaction time were studied by single factor experiment and orthogonal test. The effects of calcination temperature and calcination time on the photocatalytic performance of TiO2 were discussed. Secondly, titanium dioxide with different doping amounts of cobalt ions was prepared by using the optimum reaction conditions obtained before. The crystal form and internal structure of the samples were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Elemental analysis of the sample was carried out by EDS. The effect of doping amount of cobalt ion on the photocatalytic performance of the sample was studied with methylene blue as the target degradation material. The optimum doping amount of cobalt ion was obtained, and the degradation rate of methylene blue was the highest in the sample. Thirdly, the effects of light source, initial concentration of methylene blue and amount of photocatalyst on photocatalytic reaction were studied. The experimental results show that when the concentration of hydrothermal reaction lye is 10 mol / L, the hydrothermal reaction temperature is 130 鈩，

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