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天然矿物负载TiO2的光催化功能材料研究
The Study on the Preparation of TiO2/Mineral and Photocatalytic Degradation of Methyl Orange
【作者】 刘勋;
【作者基本信息】 四川大学 , 材料学, 2003, 硕士
【摘要】 纳米或纳米晶TiO2具有安全、无毒、成本低、无二次污染,且具有抗菌、消毒功能,它是迄今为止最有效的新型光催化剂和无机抗菌剂之一。目前,纳米TiO2的制备主要是利用液相法。本文针对在液相法制备纳米二氧化钛时,如何进一步降低生产成本,提高产物液固分离效率,以及改善二氧化钛纳米粒子的分散性和光催化效果等问题,采用天然矿物为载体,以工业偏钛酸和黑钛液为原料,从天然矿物筛选、功能材料制备工艺研究和制备方法比较、产品的光化活性等三个方面进行了研究。 本文通过硅藻土、海泡石、蛭石、硅灰石、高岭石、膨润土等六种矿物对TiO2的吸附效果及吸附量的比较,对天然矿物进行了初步筛选。并进一步研究了球磨、浮选和重选、酸处理、热处理等前处理对天然矿物的比表面和吸附性的影响,并着重讨论了前处理条件对硅藻土和海泡石的吸附性能的影响。 在TiO2/天然矿物纳米功能材料的制备方面,本文从TiOSO4的制备开始着手,以天然矿物硅藻土为载体,研究了纳米功能材料的四种制备方法,即:中和水解法、均匀沉淀法、强迫沸腾回流水解法和过氧化钛溶胶法。并分别实验研究了钛液起始浓度、反应液起始酸度、反应温度、反应时间等实验条件对产品光化活性的影响,并对各制备方法进行实验条件优化和优劣比较。在本节最后,进行了实验室公斤级样扩试实验。 在产品对有机物的光降解方面,本文主要以产品光降解甲基橙溶液为例,研究了光降解过程中,有机物浓度与时间的关系。并在此基础上,对有机物浓度与时间的曲线进行了动力学处理,得出产品光降解甲基橙的动力学过程分为三步,摘要即:高浓度时的零级反应、中等浓度时的二级反应和低浓度时的一级反应。在产品光降解甲基橙溶液过程中,本文还研究比较了溶液的PH值、反应温度等实验条件对光降解效果的影响。
【Abstract】 Nanometer TiO2 has the following properties: safety, innocuity, low-cost and no secondary pollution, and it also has the functions of antibiosis and antisepsis. It is one of the photocatalyst of new pattern and the inorganic antisepsis with the most efficiency. Now, the preparation of nanometer TiO2 is mainly via liquid phase methods. Aiming at the problems of reducing cost, increasing the separation efficiency of the solid and liquid, and improving the disperse rate and the photocatalytic effect of nano-TiO2 when synthesizing in liquid phase, this dissertation, taking the natural minerals as carrier and the industrial metatitanic acid and the industrial black titanic liquid as the raw material, has studied the selection of the nature mineral, the methods and the conditions of the preparation of TiO2/mineral with nano-structure and the photocatalysis of the product.By being compared the adsorbent rate to TiO2, the minerals (diatomite, sepiolite, vermiculite, grammite, kaoline, bentonite) has selected elementarily in the paper. And the effects of ballmilling, floatation and weight-selection, acid treatment and heat treatment on the specific surface and adsorbability of the natural minerals have been studied further, especially on diatomite and sepiolite.About the preparation of the material, this dissertation stared with the preparation of TiOSO4, and, taking the diatomite as the carrier, has studied the four preparationmethods: neutralizing hydrolysis, homogeneous precipitation, forced hydrolysis under boiling reflux conditions and titanium peroxide sol method. In this dissertation, the synthesized conditions, such as the initial concentration of Ti4+, the initial acidity, the reactive temperature and the reactive time, have been studied with their effects on the photochemical activity of the product and the four preparation methods have been compared and optimized. In the last of this chapter, the study of the extension preparation on the scale of kilogram in laboratory has been carried out.In order to study the photochemical activity of the product further, this dissertation, taking methyl orange as a deputy of organism, has studied the relation between the concentration of the organism and the reactive time during the process of light degradation, and, on the basis of the relation, the kinetic process of the photocatalytic degradation was achieved by the treatment on the curve of the organism concentration to the reactive time: zero order reaction of the high organism concentration, first order reaction of the middle organism concentration, second order reaction of the low organism concentration. In addition, the paper has studied and compared the reactive conditions’ effects on the efficiency of the photocatalytic degradation, such as the pH value and the reactive temperature.
【Key words】 TiO2; mineral; diatomite; preparation; Photocatalytic degradation; methyl orange;
- 【网络出版投稿人】 四川大学 【网络出版年期】2004年 01期
- 【分类号】TB34
- 【被引频次】9
- 【下载频次】567