更新时间:07-05 上传会员:飞舞的丝带
分类:环境科学 论文字数:29931 需要金币:1000个
摘 要:伴随着人类物质文明的进步与发展,带来了越来越多的环境污染。人们经过长期努力,已经建立了许多治理环境污染物的方法,例如纳米TiO2等半导体的异相光催化降解有机污染物。因其速度快、无选择性、深度氧化完全、能充分利用廉价太阳光和空气(水相中)的氧分子等优点而倍受青睐。美国、日本和加拿大等国已将半导体光催化技术应用于环保领域,目前国内对该技术大都还只限于实验室研究水平。
本论文主要研究TiO2光催化剂的制备及掺杂改性,内容分为三个部分:
第一部分,选题的目的和意义;国内外光催化技术的研究现状:半导体的光催化作用原理,光催化剂的制备,光催化材料的物化性质,光催化技术的应用;光催化剂的可见光化研究:染料光敏化,离子掺杂,贵金属沉积;光催化剂的载体选择及负载技术:TiO2光催化剂的载体,固定相TiO2的制备方法。
第二部分,主要研究方法和研究内容:TiO2光催化薄膜的制备及改性;TiO2的研究方法和技术路线;TiO2实验的药品及装置。
第三部分,采用溶胶-凝胶法,利用四氯化钛为原料,无水乙醇为抑制剂,制备TiO2光催化剂,以对亚甲基蓝的降解考察不同载体、不同制备条件及不同改性方法对TiO2光催化活性的影响。实验结果表明,当pH为7,在400℃煅烧1h生成的TiO2薄膜的光催化性能最好,出现了以锐钛矿为主的TiO2颗粒,此时对亚甲基蓝的降解效果最好,3h内可降解60%的亚甲基蓝。
以Pt和Au对TiO2掺杂改性。结果表明,Pt和Au的掺杂都在一定程度上改善了TiO2的光催化活性,相比而言Pt的改性效果更好。且当Pt光沉积时间为60min时,对亚甲基蓝的降解效果最佳,3h内可降解79.3%的亚甲基蓝。
关键词:光催化,TiO2,制备,表征,改性,可见光
Abstract:With the advancement and development of modern industry, increasing environmental problems are brought out. There are many methods for disposing contaminations, among which the multiphase photocatalysis for the degradation of contaminations of nano TiO2 is superior. This method has high activity, no selectivity, complete oxidation, sunlight and oxygen’s application(in water phase). American, Japan and Canada use the technology of semiconductor photocatalysis for environmental protection. But now, the research level of this technology is limited in the laboratories in China.
The modification by doping, preparing and immobilization of titanium dioxide and InVO4 have been mainly studied in the paper, which content have been divided into three parts.
In first part, the purpose and significance of the topics; photocatalytic technology at home and abroad Research: semiconductor photocatalysis principles, Photocatalyst, the physical and chemical properties of the photocatalytic materials, photocatalytic technology; visible light photocatalyst: dye sensitization, ion doping, noble metal deposition; the photocatalyst carrier selection and load technology: the TiO2 photocatalyst carrier, the preparation method of the stationary phase TiO2.
In sceond part, Main research methods and content: TiO2 photocatalytic thin films and modified; TiO2 research methods and technology roadmap; TiO2 experimental drugs and devices.
In third part, nanometer titania Photocatalyst was synthesized by means of sol-gel using tetrachloride titanate as material and grain alcohol as inhibitor to study its Photoeatalytic Performance through degrading methylene blueness. Both the influence of synthesis condition on titania crystal structure, granularity and the influence of calcination on crystal structure were studied. The results show that when the pH is 7 and firing at 400℃, the photocatalytic performance is the most, and the anatase titanium dioxide was mainly formed and the rutile has appeared a little. Degradation radio of methylene blue is 60% in three hours.
Use Pt and Au to modify titania. The results show that the Titania’s construction get polished up, which would have more hydroxyl radicals. The modification effect of Pt is better. Degradation radio of methylene blue is 79.3% in three hours.
Key Words:photocatalysis, Titanium dioxide, Preparation, Characterization, modification, visible light