基于天然纤维素物质的二氧化钛纳米复合材料的制备及性质研究

发布时间：2018-03-09 13:32

本文选题：二氧化钛　切入点：纤维素　出处：《浙江大学》2015年博士论文　论文类型：学位论文

【摘要】：伴随着全球经济和工业的飞速发展,化石燃料等不可再生燃料将日趋枯竭,环境污染等问题也日益严重,因此人们开始致力于研究开发环境友好型的功能性材料。纤维素物质广泛存在于自然界中,具有无毒性、柔韧性、多孔性、生物降解性和相容性等优点,因此,可以利用纤维素为模板或支架,将客体材料引入纤维素的独特天然结构中,制备新型纤维素功能材料。二氧化钛纳米材料由于具有独特的物理化学性质而广泛应用于光催化、抗菌、太阳能电池以及锂离子电池等方面的研究。本文以天然纤维素(普通定量滤纸)为模板或支架,以钛酸四丁酯为前体物,通过表面溶胶-凝胶的方法在纤维素纳米纤维的表面沉积二氧化钛超薄凝胶膜,随后通过不同的后处理方法,得到了各种具有特定性质和结构的二氧化钛功能复合材料,主要结论如下：1、金红石型二氧化钛/石墨复合材料：将通过表面溶胶-凝胶法制备的二氧化钛凝胶膜/纤维素复合材料在1300℃,Ar氛围中碳化,得到了金红石型二氧化钛/石墨复合材料。碳化过程中,纤维素纳米纤维转变成具有核壳结构的碳纤维,与此同时,无定型的二氧化钛超薄凝胶膜转变成金红石型二氧化钛纳米颗粒。由于二氧化钛凝胶膜和纤维素的协同作用,阻止了纤维素纳米纤维和二氧化钛在碳化过程中的烧结和聚集,使得该金红石型二氧化钛/石墨复合材料具有较大的比表面积。将该复合材料用于亚甲蓝水溶液的脱色研究,结果表明其对亚甲蓝水溶液在高压汞灯照射下的脱色具有较好的催化效果。此外,由于金红石型二氧化钛/石墨复合材料中含有石墨型的碳,因此其还具有一定的导电性。2、锐钛矿/金红石型二氧化钛纳米管复合材料：将通过表面溶胶-凝胶法制备的二氧化钛凝胶膜/纤维素复合薄片在空气中煅烧,得到了锐钛矿型二氧化钛纳米管,随后以钛酸四丁酯为前体物,通过水热的方法,在锐钛矿型二氧化钛表面生长金红石型二氧化钛,得到了异质结构的锐钛矿/金红石型二氧化钛复合材料。这样的一种异质结构有利于实现光生电子和空穴的分离,提高材料的光催化活性。光催化实验结果表明,锐钛矿/金红石型二氧化钛复合材料对亚甲基蓝分子的光降解显示了很好的催化效果。3、锐钛矿型二氧化钛/纤维素复合材料：通过两种不同的方法制备了锐钛矿型二氧化钛/纤维素复合材料。(1)将通过表面溶胶-凝胶法制备的二氧化钛凝胶膜/纤维素复合薄片在水和乙醇介质中进行水热反应,制备了锐钛矿型二氧化钛/纤维素复合材料。在水热反应过程中,超薄的二氧化钛凝胶膜转变成了锐钛矿型二氧化钛纳米颗粒,均匀地分散在每根纤维素纳米纤维的表面。由于该锐钛矿型二氧化钛/纤维素复合材料具有较大的比表面积,有利于染料分子的吸附,提高了材料的光催化效果。光催化实验结果表明,该材料对亚甲蓝和甲基橙分子的降解都具有较好的光催化效果。(2)以二氧化钛凝胶膜/纤维素复合材料为模板,加入至含有钛酸四丁酯的乙醇溶液中,通过溶剂热的方法将钛酸四丁酯均匀地吸附在纤维素纳米纤维的表面,随后进行水热反应,将钛酸四丁酯转变成了锐钛矿型二氧化钛纳米颗粒,得到了锐钛矿型二氧化钛/纤维素复合材料。这种方法解决了钛酸四丁酯在水溶液中因快速水解而导致颗粒聚集的问题。天然纤维素的多级层次网状结构为钛酸四丁酯提供了很多吸附通道,纤维物物质的纳米孔隙结构又可以为钛酸四丁酯的水解提供细小的空间,阻止了大颗粒二氧化钛的形成,因此通过这种方法制备的二氧化钛纳米颗粒的粒径很小,具有较大的比表面积,使得该材料对有机染料的降解具有较好的光催化效果。此外,通过光还原的方法在锐钛矿型二氧化钛/纤维素复合材料表面修饰银纳米颗粒,得到了锐钛矿型二氧化钛/纤维素-银纳米颗粒复合材料,该材料对大肠杆菌和金黄色葡萄球菌都具有较明显的抗菌效果。4、锐钛矿/金红石型二氧化钛-银纳米颗粒复合材料：通过银镜反应,将银纳米颗粒修饰到结论2中制备的锐钛矿/金红石型二氧化钛复合材料的表面,得到了锐钛矿/金红石型二氧化钛-银纳米颗粒的复合材料。由于锐钛矿/金红石型二氧化钛复合材料的比表面积比较大,导致其银的负载量比较大,提高了锐钛矿/金红石型二氧化钛复合材料的导电性。将该复合材料应用于锂离子电池负极材料的性能研究,结果表明,该复合材料显示了较好的循环稳定性和倍率性能。5、二氧化钛/氧化铟锡复合材料：以锐钛矿型二氧化钛纳米管为基体,在苯甲醇溶液中分别加入乙酰丙酮铟和叔丁氧基锡两种前体物,通过溶剂热的方法将氧化锢锡纳米颗粒均匀地负载在二氧化钛纳米管的表面,得到了具有多级层次结构的二氧化钛/氧化铟锡复合材料。将该复合材料应用于锂离子电池负极材料的性能研究,结果表明,该复合材料不仅具有较高的比容量,还显示了较好的循环稳定性和倍率性能。
[Abstract]:With the rapid development of the global economy and industry, fossil fuels and other non renewable fuel depletion, environmental pollution and other issues are also increasingly serious, functional material so people begin to study the development of environmentally friendly. The cellulose material widely exists in nature, is non-toxic, flexible, porous, biodegradable and biocompatibility, therefore, cellulose can be used as a template or a bracket, a unique natural cellulose material into the object structure, the preparation of a new type of cellulose functional materials. Nano TiO2 due to the unique physical and chemical properties and is widely used in photocatalytic, antibacterial, solar batteries and lithium ion batteries and so on. The natural cellulose (common quantitative filter paper) as a template or stent, with four butyl titanate as precursors by sol-gel method on the surface of fiber The surface deposition of titanium dioxide thin film Sunami gel fibers, followed by different postprocessing methods, the function of various kinds of composite materials of titanium dioxide with specific properties and structure, the main conclusions are as follows: 1, rutile titania / graphite composite materials: through titania sol-gel film / surface prepared by sol-gel method in cellulose composites 1300 degrees, Ar carbonation atmosphere, the rutile titania / graphite composite materials. During carbonization of cellulose nanofiber into carbon fibers with core-shell structure, and at the same time, no titanium dioxide gel film ultrathin amorphous transformed into rutile titanium dioxide nanoparticles. Due to the synergistic effects of titania gel and cellulose membrane stop, sintering cellulose nano fiber and titanium dioxide in the carbonization process and aggregation, makes the rutile oxide two Titanium / graphite composite material has larger surface area. The composite material used for decolorization of methylene blue in aqueous solution, the results show that it has better catalytic effect on the decolorization under high pressure mercury lamp of methylene blue aqueous solution. In addition, the rutile titania / graphite composite materials containing carbon graphite therefore, it also has certain conductive.2, anatase / rutile titania nanotube composite materials: titanium dioxide gel film surface by sol-gel / cellulose composite sheet calcined in air, the anatase type TiO2 nanotubes, followed by four butyl titanate as precursor by hydrothermal method in surface growth of anatase titanium dioxide, rutile titanium dioxide, the heterogeneous structure of anatase / rutile titanium dioxide composite material. Such a heterogeneous structure Is conducive to the realization of the separation of photogenerated electrons and holes, improve the photocatalytic activity of the material. The experimental results show that the photocatalytic degradation, anatase / rutile titanium dioxide composite of methylene blue molecules showed good catalytic effect of.3 anatase TiO2 / cellulose composite material by using two different preparation methods the anatase TiO2 / cellulose composite material. (1) by titania sol-gel film / surface sol-gel composite sheet of cellulose in water and ethanol medium by hydrothermal reaction, anatase TiO2 / cellulose composite material was prepared. During the hydrothermal process, titanium dioxide thin film forming gel transition the anatase TiO2 nanoparticles, surface uniformly dispersed in each cellulose nanofibers. The anatase TiO2 / cellulose composite material Has a larger surface area, which is helpful to the adsorption of dye molecules, improve the photocatalytic activity of the material. The experimental results show that the photocatalytic degradation of the material, methylene blue and methyl orange molecules have better photocatalytic effect. (2) using titanium dioxide gel film / cellulose composite material as template, ethanol solution added to contain four butyl titanate in the solvothermal method to four butyl titanate uniformly adsorbed on the surface of cellulose nanofibers, followed by hydrothermal reaction, converting four butyl titanate to anatase TiO2 nanoparticles, obtained anatase TiO2 / cellulose composites. This method can solve the titanate four butyl in aqueous solution by rapid hydrolysis due to particle aggregation problems. Provides a lot of adsorption channel multi-level network structure of cellulose for four butyl titanate, fiber material The hydrolysis of nano pore structure quality but also can provide four butyl titanate fine space, prevents the formation of large particles of titanium dioxide, so the titanium dioxide nano particles prepared by this method the particle size is very small, with a large specific surface area, so that the material has better catalytic effect on degradation of organic dyes. In addition, through the method of light reduction in anatase TiO2 / cellulose composite surface modified silver nanoparticles, obtained anatase TiO2 / cellulose - silver nano particle composite material, this material has obvious antibacterial effect of.4 on Escherichia coli and Staphylococcus aureus, anatase / rutile TiO2 Ag nanoparticles composite materials: the silver mirror reaction, the silver nanoparticles modified surface to the conclusion 2 preparation of anatase / rutile titanium dioxide composite material, get The anatase / rutile TiO2 Ag nanoparticles composite materials. Because of anatase / rutile titanium dioxide composite surface area is relatively large, resulting in a load of the silver is relatively large, improving the conductivity of anatase / rutile titanium dioxide composite material. The performance of the research and application of composite materials in anode materials for lithium ion the results show that the battery, the composite shows good cycling stability and rate performance of.5, TiO2 / ITO Composite with anatase TiO2 nanotubes as matrix in benzyl alcohol solution were added acetylacetone and t-butoxy indium tin two precursor by solvothermal method on the surface indium tin oxide nano particles supported on TiO2 nanotubes, the TiO2 / has a multilevel structure of indium tin oxide composite material. The complex The composite material is applied to study the performance of anode materials for lithium ion batteries. The results show that the composite has not only high specific capacity, but also good cycling stability and rate performance.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ134.11;TB33

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