【作者】 于静；

【导师】 魏雨；

【作者基本信息】 河北师范大学 ， 物理化学， 2004， 硕士

【摘要】 纳米二氧化钛是一种附加值很高的重要无机材料。由于其比表面积大，表面活性高，耐候性和耐腐蚀性良好，抗紫外线能力强等优点广泛应用于涂料、化妆品、感光材料、催化剂、环境工程、食品包装、医药等领域。由于各种应用都与粉体的晶型和形貌等性能有直接关系，因此纳米TiO₂粉体的制备成为了纳米材料科学的一个研究热点。 金红石型纳米二氧化钛具有折射率高，耐热性能好，化学性质稳定等优点，而目前人们对其制备的研究相对较少。现有的制备金红石型TiO₂粉体的各种方法大多需要高温煅烧，而这样会引起粉体的烧结，并且应用上也受到了限制。基于以上原因本论文对金红石型氧化钛的制备进行了研究，以TiCl₄为前驱物，利用低温陈化和沸腾回流法制备出了金红石型纳米TiO₂。这两种方法具有工艺简单，反应速度快，温度低等优点，从而为纳米二氧化钛的工业化生产提供了理论和实践依据。 本论文的主要研究内容： （1） 陈化法制备金红石型纳米二氧化钛 采用低温陈化强迫水解法，通过实验系统研究了各种反应条件如反应物初始浓度，反应温度，反应初始酸碱度等对产物的影响，从而确定了有利于金红石型纳米TiO₂生成的条件。实验结果表明：体系初始Ti⁴⁺浓度高，反应温度低，体系酸度高以及加入金红石型TiO₂晶核均有利于金红石型纳米TiO₂的合成；在静态陈化的条件下，得到金红石型产物形貌为针形，而在加入搅拌的情况下能够得到分散性较好的球形微粒。 首次利用简单的陈化方法在液相中一步合成了会红石型TiO₂晶须。寻找到了低温合成晶须的最佳条件：[Ti⁴⁺]=2.0mol／L，陈化温度70℃。用电子衍射对晶须进行了表征，证明其晶化较好。 （2） 沸腾回流强迫水解法制备金红石型纳米二氧化钛 利用沸腾回流法，通过实验研究了反应物初始浓度，升温速率对二氧化钛晶型和形貌的影响。当钛离子浓度为0.9mol／L，控制一定的升温速率合成了粒径为10nm左右的金红石型纳米TiO₂球。 （3） 添加磷酸根制备球形二氧化钛微粒 利用强迫水解法分别在反应体系中添加磷酸，磷酸二氢钠，有机二磷酸控制二摘要氧化钦的粒径。研究了反应物初始浓度，添加剂浓度对产物粒径的影响，当钦离子浓度为10mol/L左右，[Ti，+]:[P 043一卜1:0.02时，得到的球形较为均匀，晶型为混晶。 利用磷钥蓝分光光度法探讨了磷酸根离子对反应过程中的影响作用。 为了得到金红石型Tio:，我们对得到粉体进行锻烧，发现Po43一离子的添加对锐钦矿型Tio:具有稳定作用，且在一走的添加浓度有从金红石相向锐钦矿相转化的趋势。更多还原

【Abstract】 The nanometer titania is an important high performance fine inorganic materials. Because of its advantages, such as big specific surface area, high surface activity, good resistance to weathering, chemical resistance and good uvioresistant properties, nanosized TiO2 is applied in pianting materials, cosmetic, photosensitive materials, photocatalyst, project of environment, peeking material of the food and medicine field and so on. All kinds of these applications are connected with the crystal structure and shape of nanopowder, so the preparation of nanometer titania has become a research hot spot of nano-material science.Rutile TiO2 has many advantages, such as high refractive index, good heat resistance and stable chemical properties. But nowadays, few people research on the preparation of rutile TiO2 powders. Most of the methods to prepare rutile TiO2 need high-temperature calcination, but in this way it will cause agglomeration of the powders. This will limit the powder application. Based on the above reasons, we studied the preparation of rutile TiO2 powders. We selected TiO2 as precursor and got the products by boiling reflux and aging method. These two methods have such outstanding characteristics as simple equipment, fast rate of reaction and low reaction temperature etc. And all of these characteristics may offer the theoretical and practical basis for industrial production.The main research aspects are as follows:(1)The preparation of rutile titania by aging methodThe nanometer titania powders were prepared by aging at low temperature. The influences of reactant initial concentration, reaction temperatrue, reaction pH value etc were studied. The optimum condition of rutile titania were determined. The results as follows: higher initial concentration of reactant, lower reaction temperature, lower pH value and adding rutile seeds would have benefit to preparation of rutile TiO2 powders. The products we got under this condition of static state were needle-shaped, but when stirring, the shape became sphere.We synthesized the rutile TiO2 whisker by the simple aging method in the liquid phase, and found the appropriate reaction condition: [Ti4+]=2.0mol/L , temperature was70 C. Electron diffraction was used to characterize the whiskers. (2)The preparation of rutile titania by boiling reflux method.The nanometer titania powders were prepared by forced hydrolysis under boiling reflux method. In the experiment, the influences of reactant initial concentration, temperature rising rate were studied. Finally, we got the rutile TiO2 sphere of the particle size of 10nm with [Ti4+]=0.9mol/L and certain temperature rising rate.(3)The preparation of sphere-shaped titania by adding PO43-We controlled the size of titania by adding different concentration of H3PO4, NaH2PO4 and HEDP. The influences of reactant initial concentration, additive concentration on the particle size were researched. When the concentration of Ti4+ was about 1.0mol/L and [Ti4+].- [PO43-]=1: 0.02, we got the uniform sphere-shaped and mixed crystal titania.Studying the influences of adding PO43- by phosphomolybdate blue spetrophotometric method.We calcined the powders to get rutile TiO2, and found that the addition of PO43- had the stable effects of anatase TiO2. At certain additive concentration, some rutile TiO2 even transformed to anatase TiO2更多还原