二氧化钛纳米带及其复合材料的制备与性能研究

发布时间：2018-01-11 19:14

本文关键词：二氧化钛纳米带及其复合材料的制备与性能研究　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：工业发展带来社会进步的同时,也造成了诸多环境问题的产生。有机染料是纺织产业产生的工业废水中的常见污染物,即使少量的有机染料也会造成大面积的水体污染,对水环境及人体健康造成危害。传统的水污染处理方法虽工艺纯熟,但是存在着处理步骤繁琐或者处理效果欠佳的缺点。半导体光催化技术可以对有机废水进行深度处理,处理效率较高。二氧化钛纳米材料无毒、易制备、价廉,是常用的光催化剂之一。工业二氧化钛粉末(P25)的光催化效果好,但是其纳米粒径小,难回收,直接将P25用于光催化水处理不仅会增加治理成本,而且有可能对水体产生二次污染。一维二氧化钛纳米材料因为其特殊的形貌,容易通过过滤回收,近年来被人们广泛研究。同时,空气污染问题催生气体传感器快速发展。在气敏传感器中,气敏材料是最核心的部分。二氧化钛既是良好的光催化剂,又对多种气体具有气体敏感性,是一种多功能的纳米材料。同二氧化钛纳米颗粒相比,一维二氧化钛纳米材料的载流子容易沿着长轴方向移动,降低了由于大量晶界存在而损失电子的可能性,理论上是更为理想的气敏材料。所以,本课题通过简单水热法制备出二氧化钛带状材料,以此为研究基体对TiO_2纳米带进行了表面粗化、掺杂改性、半导体复合等工作,以期提高其光催化性能、气敏性能及可回收性能。本文的具体研究内容和结果如下:(1)用酸辅助法制备出表面粗化的二氧化钛纳米带。所制备的纳米带主要为锐钛矿型,纳米带长达数微米至数十微米,直径为100-200 nm,表面粗糙。对制备的粗化二氧化钛进行了光催化和气敏性能的测试结果表明,制备的表面粗化的二氧化钛纳米带具有较好的光催化和气敏性能。通过改变水热时间,酸蚀时间以及煅烧温度等实验参数,研究了其对二氧化钛纳米带的微观形貌和光催化性能的影响。研究结果表明,随着水热时间的增加,纳米带有向纳米管发展的趋势;酸蚀时间越长,光催化性能越好,但是当酸蚀时间为24 h时,纳米带的带状结构会遭到破坏;煅烧温度为500 oC,钛酸带可由钛酸转变成为锐钛矿晶型,继续增加煅烧温度,纳米带带状结构被破坏,锐钛矿相向金红石相转变。(2)用简单的酸蚀辅助法制备出表面粗糙的二氧化钛纳米带,在此基础上用共沉淀法制备出双组份Fe_3O_4-TiO_2,并对其用贵金属银进行表面修饰,得到Ag@Fe_3O_4-TiO_2一维磁性可回收光催化纳米材料。所制备样品的带状直径为100-200 nm,纳米带表面纳米粒子直径为5-30 nm。三组份Ag@Fe_3O_4-TiO_2一维纳米材料不仅具有良好的光催化性能,同时具有磁性,可以用吸铁石将其从溶液中分离出来。三组份Ag@Fe_3O_4-TiO_2光催化活性的增加的原因是由于Ag在纳米带表面形成陷阱,捕捉光生电子,有效防止了电子-空穴对的复合湮灭。(3)用简单水热法制备了二氧化钛纳米带,在此基础上用浸渍烧结法制备了Zn O/TiO_2纳米材料。所制备带状样品的直径为100-200 nm,Zn O/TiO_2纳米材料表面氧化锌纳米粒子直径为40-50 nm。同纯相二氧化钛纳米带相比,一维复合Zn O/TiO_2纳米材料不仅具有更好的光催化活性(80 min内Zn O/TiO_2纳米材料对罗丹明B的紫外光降解率为94.4%,而在相同的时间内二氧化钛纳米带罗丹明溶液的降解率为85.0%),其对丙酮气体的气敏性能也有所提高(更低的工作温度,好的选择性,更短的响应恢复时间)。
[Abstract]:Bring the social progress and industrial development, also caused many environmental problems. Organic dyes are common pollutants in industrial wastewater generated in the textile industry, even a small amount of organic dyes can cause a large area of water pollution, the harm to the water environment and human health. Although the traditional method of water pollution treatment technology proficient. But there is a poor treatment or treatment effect of tedious steps shortcomings. Semiconductor photocatalytic technology can be used for advanced treatment of organic wastewater, high processing efficiency. Titanium dioxide nano materials are non-toxic, easy preparation, low price, light is one of the commonly used industrial catalyst. TiO2 powder (P25) photocatalytic effect is good, but the size of nanoparticles small, difficult to recycle, directly to the P25 for photocatalytic water treatment will not only increase the cost of governance, and may have two pollution of water bodies. One dimensional two titanium dioxide nano material The material because of its special morphology, easily recovered by filtration, have been widely studied in recent years. At the same time, the problem of air pollution led to the rapid development of gas sensors. In gas sensor, gas sensitive material is the core part. Titanium dioxide photocatalyst is good, but also has the gas sensitivity to gases, is a nano material multi function. Compared with the TiO2 nanoparticles carrier, one-dimensional TiO2 nanometer material easily along the long axis direction, reduces the loss due to the large number of grain boundary and electronic possibility theory is more ideal gas sensitive materials. Therefore, this paper through a simple hydrothermal method to prepare titanium dioxide strip material to the surface of the coarse as the research base of TiO_2 nanobelts, doping, composite semiconductors and so on, in order to improve its photocatalytic properties, gas sensitivity and Recyclable. . the specific contents and results are as follows: (1) by acid assisted preparation of nano titanium dioxide surface roughening zone. The nano belt is mainly anatase nano with tens of microns to tens of microns in diameter, 100-200 nm, surface roughness of TiO2 were prepared by coarsening the photocatalytic and gas sensing properties of the test results show that the TiO2 surface roughening preparation with high photocatalytic and gas sensing properties. By changing the hydrothermal time, experimental parameters of etching time and calcination temperature, influence of microstructure and photocatalytic properties of two titanium dioxide nanobelts the results show that, with the increase of hydrothermal time, with the trend of the development of nanotube to nano; etching time is longer, the photocatalytic performance is better, but when the etching time is 24 h, the zonal structure nano belt will be destroyed; The calcination temperature is 500 oC, can be transformed into titanate with titanate anatase, continue to increase in calcination temperature, nano strip structure was destroyed, the transformation of anatase to rutile. (2) by acid assisted method simple prepared titanium dioxide nano rough surface with prepared two-component Fe_3O_4-TiO_2 by co precipitation on this basis, and the noble metal silver surface modification, Ag@Fe_3O_4-TiO_2 one-dimensional magnetic Recyclable photocatalytic nano materials. The diameter of the samples prepared for 100-200 band nm, the surface of the nanoparticle with diameter of 5-30 nm. three component Ag@Fe_3O_4-TiO_2 one-dimensional nano material has good photocatalytic properties, it is magnetic you can use the magnet, separated from the solution. The three component due to the increase in the photocatalytic activity of Ag@Fe_3O_4-TiO_2 is due to Ag in the nanobelts formed on the surface of the trap, capture The photogenerated electrons, effectively prevent the recombination of electron hole pairs annihilation. (3) by a simple hydrothermal preparation of TiO2 nanobelts, on the basis of Zn was prepared by impregnation sintering of O/TiO_2 nano materials. The prepared samples with diameter of 100-200 nm, Zinc Oxide Zn O/TiO_2 nano material surface diameter of 40-50 nanoparticles nm. with pure TiO2 nanobelts compared the photocatalytic activity of Zn nano O/TiO_2 one-dimensional composite material not only has better (UV degradation of Luo Danming B 80 min Zn O/TiO_2 rate was 94.4% and the titanium dioxide nano materials, at the same time with the degradation of nano Luo Danming solution was 85%), the acetone gas sensitive performance also improved (lower working temperature, good selectivity, shorter response time and recovery time).

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;TB33

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