几种无机纳米材料的制备及光催化性能研究

发布时间：2018-01-06 11:10

本文关键词：几种无机纳米材料的制备及光催化性能研究　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：光催化技术能有效将太阳能转换为化学能,降解废水中的有机、部分无机和重金属污染物,是同时解决能源和环境问题的新型方法之一。人们开发的光催化剂以无机半导体纳米材料为主,例如金属氧化物、硫化物以及氮氧化物等。此类半导体具有化学稳定性高、生物相容性好、价格低等优点。但同时具有只对紫外光响应,光吸收范围窄的缺点,不能有效利用太阳能,严重制约了其实际应用。因此,改进传统光催化剂的性能以及探索高效实用的新型光催化剂尤为重要。本文研究了稀土掺杂二氧化钛(TiO_2:RE)和TiO_2/SiO_2复合纳米材料、铋盐纳米材料以及石墨烯-金属氧化物复合纳米材料的光催化活性。具体内容如下:(1)以碳微球为模板,溶剂热法制备出TiO_2:RE和TiO_2/SiO_2中空微球。采用X射线衍射、透射电子显微镜和紫外-可见漫反射光谱分析三种测试手段对产物进行相关表征,并研究了其在光照下对罗丹明B染料的降解性能。结果表明:成功制备了两种具有中空结构的产物,且尺寸均一;稀土的掺杂和SiO_2的复合都扩展了TiO_2的光响应范围。五种TiO_2:RE中空微球中,TiO_2:La中空微球的光催化活性最强。研究SiO_2的复合量对TiO_2光催化活性的影响表明:TiO_2和SiO_2的质量比为2:1时,光催化活性最好。两种产物均具有良好的重复使用性。(2)一步溶剂热法制备了Bi_2MoO_6、Bi_2Mo_2O_9微球和Bi_2MoO_6/Bi_2O_3复合中空微球。采用X射线衍射、扫描电子显微镜、透射电子显微镜、紫外-可见漫反射光谱分析和荧光光谱分析对产物进行表征,并研究了样品在可见光照下对罗丹明B的降解性能。结果显示:成功制备了Bi_2MoO_6、Bi_2Mo_2O_9微球和具有中空结构的橄榄球形Bi_2MoO_6/Bi_2O_3复合纳米颗粒,尺寸均一。三种产物都对可见光响应,Bi_2MoO_6/Bi_2O_3复合中空微球的光催化活性最强,且具有良好的化学稳定性。(3)以硫脲为硫源、乙二醇为溶剂,一步溶剂热法制备了rGO/ZnS复合材料。采用X射线衍射、透射电镜、紫外可见漫反射光谱分析和荧光光谱分析对产物进行表征,在紫外光照下对罗丹明B进行降解研究其光催化性能。结果显示:尺寸均一的ZnS纳米颗粒附着在石墨烯的表面,石墨烯的复合提高了产物的光催化活性。研究石墨烯的复合量对ZnS光催化活性的影响表明:石墨烯的掺杂量为14%时,光催化活性最强,且具有良好的重复使用性。
[Abstract]:Photocatalytic technology can effectively convert solar energy into chemical energy and degrade organic, inorganic and heavy metal pollutants in wastewater. It is one of the new methods to solve both energy and environment problems. Inorganic semiconductor nanomaterials, such as metal oxides, have been developed as photocatalysts. This kind of semiconductor has the advantages of high chemical stability, good biocompatibility and low price, but it has the disadvantage of only responding to ultraviolet light and narrow optical absorption range. It is difficult to utilize solar energy effectively, which seriously restricts its practical application. It is particularly important to improve the performance of traditional photocatalysts and to explore new photocatalysts with high efficiency and practicality. And TiO_2/SiO_2 composite nanomaterials. The photocatalytic activity of bismuth salt nanomaterials and graphene-metal oxide composite nanomaterials are as follows: 1) carbon microspheres are used as templates. TiO_2:RE and TiO_2/SiO_2 hollow microspheres were prepared by solvothermal method. The products were characterized by transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectroscopy (UV-Vis). The degradation properties of Rhodamine B dyes under light irradiation were studied. The results showed that two kinds of products with hollow structure were successfully prepared and the size was uniform. The doping of rare earth and the combination of SiO_2 both extend the range of photoresponse of TiO_2. Five kinds of TiO_2:RE hollow microspheres are found. The photocatalytic activity of TiO_2:La hollow microspheres is the strongest. The effect of the amount of SiO_2 on the photocatalytic activity of TiO_2 is studied. The results show that the mass ratio of TiO_2 to SiO_2 is 2: 1. The photocatalytic activity is the best. Both products have good reusability. 2) One-step solvothermal method was used to prepare Bi_2MoO_6. Bi_2Mo_2O_9 microspheres and Bi_2MoO_6/Bi_2O_3 composite hollow microspheres were characterized by X-ray diffraction, scanning electron microscope and transmission electron microscope. UV-Vis diffuse reflectance spectroscopy and fluorescence spectroscopy were used to characterize the product. The degradation of Rhodamine B was studied under visible light. The results showed that Bi_2MoO_6 was successfully prepared. Bi_2Mo_2O_9 microspheres and rugby shaped Bi_2MoO_6/Bi_2O_3 composite nanoparticles with hollow structure are homogeneous in size. The three products are all responsive to visible light. Bi_2MoO_6/Bi_2O_3 composite hollow microspheres have the strongest photocatalytic activity and have good chemical stability. 3) thiourea as sulfur source and ethylene glycol as solvent. RGO/ZnS composites were prepared by one-step solvothermal method and characterized by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectroscopy and fluorescence spectrum analysis. The photocatalytic properties of Rhodamine B were studied under UV irradiation. The results showed that ZnS nanoparticles with uniform size adhered to the surface of graphene. The effect of the amount of graphene on the photocatalytic activity of ZnS was studied. The results showed that the photocatalytic activity of graphene was the strongest when the doping amount of graphene was 14. And it has good reusability.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O643.36

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