纳米TiO₂催化剂的制备及用ECR氮等离子体对其改性的研究

【作者】 孔令红；

【导师】 熊予莹；

【作者基本信息】 华南师范大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 随着资源的过度利用和大自然的严重污染，生态环境遭受了严重的破坏。人们迫切需要开发能够经济有效地利用能源并具有不污染环境的功能材料。纳米TO₂正是这种具有净化环境功能的绿色材料，它可完成环境净化、能源再生、能源贮备、不污染环境等多项功效。纳米TiO₂具有无毒、催化效率高、性能稳定、价廉等突出特点以及在光催化氧化处理废水及净化空气中的应用，使它已成为目前光催化研究领域中最活跃的方向之一。但悬浮相的纳米TiO₂体系存在着催化剂难以回收、容易中毒等缺点，同时纳米TiO₂对可见太阳光的吸收很少，这也大大限制了其广泛应用。本文主要就纳米TiO₂薄膜的制备、探索用ECR氮等离子纳米TiO₂的掺杂改性等开展了如下的工作： 本文采用溶胶—凝胶法，以钛酸丁醋做前驱体、无水乙醇做溶剂，水解制备溶胶，然后通过提拉法制备纳米TiO₂薄膜。在制备薄膜的过程中研究了拉膜氛围对薄膜质量的影响，研究表明：在超声场的氛围中拉膜效果较好。 本文对用ECR等离子体注入氮改性纳米TiO₂的光吸收进行了广泛深入的研究。研究表明，注入时间和注入功率对纳米TiO₂的光吸收有较大影响，氮的注入量存在一个最佳浓度值，掺杂剂浓度太高或太低，均不利于提高纳米TiO₂的光吸收。AFM研究表明，经氮等离子体的注入没有改变催化剂的表明形貌；紫外—可见光谱分析结果表明，改性后TiO₂薄膜催化剂的光谱响应红移了12nm-18nm；通过不同功率、不同处理时间研究显示，在微波功率为400W条件下处理60分钟效果最理想；通过XPS测试分析，对其改性机理做了深入探讨：氮掺杂改性有利于提高纳米TiO₂的光吸收归因于掺杂能级的形成。 同时本文对用ECR等离子体注入氮改性纳米TiO₂的超亲水性收进行了研究。结果表明，改性后催化剂的接触角有所增加，但催化剂的超亲水性没有发生改变，同时催化剂经等离子体处理后在开放的环境中样品的接触角的变化缓慢一些。更多还原

【Abstract】 With the excessive exploitation of natural resources and grave pollution of environment, the deterioration of ecological environment becomes more and more serious. It is urgent to develop ecomaterials, which use economically energy and have no harm to environment. With its renewal ability and storability of energy and friendliness of environment, nano-semiconductor TiO2 is the very novel green purificant. Now its relevant study becomes the focus of the field of photocatalysis, especially in wastewater treatment. However, the nano-TiO2 powders in liquor are vrey difficult to recycle and easy to be poisoned. Further more, the nano-TiO2 absorbs visible light very poor. As a result, it is difficult to realize its commercialization. The pertinent research work has been carried out as follows:The transparent nano-TiO2 films on soda-lime glass substrates were obtained by sol-gel process. The precursor of nano-TiO2 film was Ti (OC4H9) 4 and the menstruum was C2H5OH. The preparation conditions which were effecting the nano-TiO2 quality were researched. The nano-TiO2 quality was improved by prepared in the ultrasonic condition.The 1 optical absorption property of nano-TiO2 film doped with nitrogen by ECR plasma was studied systematically. The research result shows that doped time and power has great effect on the 1 optical absorption of TiO2. There is the best value for dopant. Over higher or lower dopant concentration is disadvantageous for the 1 optical absorption property. The AFM scans has shown that the sample’s external configuration has not been defaced. The UV-Vis instrument test has shown that the absorb spectrum has been move 12nm-18nm to the infrared. With different power and implanting time, the feasible conditions are under the four hundred watt and sixty minutes. The reason for the nitrogen doped herein lies in the fact it contributes to formation of doped energy band. The result is detailedly proved by the XPS test.The hydrophilicity of the modified nano-TiO2 film was also studied. The ruslt shows that the hydrophilic angle has a little increase, but its super hydrophilicity is not alterant, and also shows the hydrophilic angle increasing on open entironment is slowing.更多还原