金属氧化物、硫化物纳米复合材料的合成及其性能研究

发布时间：2018-05-28 04:31

本文选题：金属氧化物 + 金属硫化物　；参考：《浙江师范大学》2015年硕士论文

【摘要】：金属氧化物如ZnO和ZnFe2O4等,金属硫化物如CuS等由于其独特的物理和化学性能,使其在光催化、光电化学及锂离子电池等领域都有广泛的应用。石墨烯作为一种拥有特殊的二维结构的碳材料,由于其突出的热稳定性、良好的导电性、结构的灵活性、超高的比表面积及其在纳米科学和技术上的广泛应用性,常被用作为基底来负载其他活泼纳米材料。本论文对不同金属氧化物和硫化物及其纳米复合材料的制备及其性能研究展开了工作,着重研究了材料的制备方法和过程,以及所制备材料的光催化性能、光电化学性能及其作为锂离子电池负极材料时的电化学性能。本论文主要研究以下几个方面的内容：1.超声法制备CuS/rGO纳米复合材料及其光催化性能研究本章中,我们首先利用超声法制备出CuS纳米颗粒覆盖的还原氧化石墨烯纳米片。通过XRD和电镜观察结果表明,粒径为10-20nm左右的CuS纳米颗粒均匀地分散在rGO纳米片上。紫外-可见光谱表明CuS/rGO纳米复合材料显示出了强而宽的光吸收能力。CuS/rGO纳米复合材料的光催化性能的表征通过检测亚甲基蓝在可见光下的降解能力来实现。光催化实验结果表明,与单纯的CuS纳米颗粒相比,CuS/rGO复合材料显示出了明显优越的性能,这主要是由于其良好的光吸收能力和染料吸附能力及由于rGO的引入而带来的有效的电荷转移。2.多孔ZnO空心球的制备及其光电化学性能研究我们采用C微球模板法制备了多孔ZnO空心球,并通过X射线衍射、扫描电子显微镜、透射电子显微镜等对其微观结构进行了分析。由分析可知,所制备的ZnO产物样品显示出了明显的空心球结构,且其球径大小在2-4um左右。ZnO空心球壳层的厚度大概为100nm左右,并且是由许多粒径在30-50nm的小纳米颗粒堆积而成的。我们研究了产物的光学性质,其结果表明所制备的ZnO空心球显示了较小的带隙,并且在434nm处呈现出较强的紫外发射。另外,该ZnO在可见光范围内表现出了强而稳定的光电流效应。材料在可见光下展现出良好的光电性能可能要归结于其较小的带隙。3.ZnFe2O4-graphene纳米复合材料的制备及其锂电性能研究’本章节中,我们以无水FeCl3、Zn(Ac)2·2H2O及无水NaAc为原料,无水乙二醇为溶剂,通过一步溶剂热法合成了ZnFe2O4-graphene纳米复合材料。通过X射线衍射、扫描电子显微镜、透射电子显微镜等对其微观结构进行了分析,并通过循环伏安法、恒电流充放电及交流阻抗等测试对材料的电化学性能进行了研究。研究结果表明,材料为直径在100nm左右的ZnFe2O4纳米球均匀地负载在石墨烯纳米片上,且其作为电池负极材料表现出了比较好的锂电性能。材料首次放电容量可达到1400mAh g-1,且在电流密度为100mAg-1下循环50次后,其容量还可以保持在704.2mAh g-1,而纯的ZnFe2O4只有121.7 mAh g-1,远远低于复合材料。即使在800mAg-1高电流密度下循环,ZnFe2O4-graphene纳米复合材料的容量也能保持在271.8mAh g-1,比纯ZnFe2O4的容量(26.6mAh g-1)高的多。材料所表现出的较好的电化学性能的主要可能是由石墨烯的良好的导电性及ZnFe2O4与石墨烯之间的相互协同作用导致的。
[Abstract]:Metallic oxides, such as ZnO and ZnFe2O4, etc., metal sulfides, such as CuS, have been widely used in the fields of photocatalysis, photoelectrochemistry and lithium ion batteries because of their unique physical and chemical properties. Graphene is a carbon material with a special two-dimensional structure, due to its outstanding thermal stability, good conductivity, and structure. Flexibility, high specific surface area and its wide application in nanoscience and technology are often used as substrates to load other active nanomaterials. The preparation and properties of different metal oxides and sulfides and their nanocomposites have been studied in this paper, and the preparation methods and processes of the materials are emphatically studied. The photocatalytic properties of the prepared materials, photoelectrochemical properties and their electrochemical properties as negative materials for lithium ion batteries. The main contents of this thesis are as follows: in the study of the preparation of CuS/rGO nanocomposites and their photocatalytic properties by the 1. ultrasonic method, we first prepared CuS nanoparticles by ultrasonic method. The results of XRD and electron microscopy showed that the CuS nanoparticles with a particle size of about 10-20nm were evenly dispersed on the rGO nanoscale. The UV visible spectra showed that the photocatalytic properties of the CuS/rGO nanocomposites showed a strong and wide absorption capacity of.CuS/rGO nanomaterials. The degradation ability of methylene blue under visible light was detected. The results of photocatalytic experiment showed that compared with pure CuS nanoparticles, CuS/rGO composite showed obvious superior performance, mainly due to its good absorbability and absorbability of dye and the effective charge transfer.2. caused by the introduction of rGO. Preparation and photochemical properties of hole ZnO hollow spheres, porous ZnO hollow spheres were prepared by C microsphere template method. The microstructure of the hollow spheres was analyzed by X ray diffraction, scanning electron microscope and transmission electron microscope. The thickness of the ball diameter at about 2-4um.ZnO hollow sphere is about 100nm, and it is formed by the accumulation of small nanoparticles with many particle sizes at 30-50nm. We studied the optical properties of the products. The results showed that the prepared ZnO hollow spheres showed a small band gap and showed strong ultraviolet emission at 434nm. The ZnO shows a strong and stable photocurrent effect in the range of visible light. The good photoelectric performance of the material under visible light may be attributed to the preparation of its smaller band gap.3.ZnFe2O4-graphene nanocomposites and the study of their lithium electrical properties. In this chapter, we use anhydrous FeCl3, Zn (Ac) 2. 2H2O and anhydrous NaAc as raw materials ZnFe2O4-graphene nanocomposites were synthesized by one step solvothermal method with anhydrous glycol as solvent. The microstructure was analyzed by X ray diffraction, scanning electron microscope and transmission electron microscope, and the electrochemical properties of the materials were tested by cyclic voltammetry, constant current charge discharge and current impedance. The results show that the ZnFe2O4 nanospheres with a diameter of about 100nm are uniformly loaded on the Shi Moxi nanoscale, and their battery negative electrode exhibits good lithium electrical properties. The initial discharge capacity of the material can reach 1400mAh g-1, and the capacity of the material can be maintained after 50 cycles under the current density of 100mAg-1. At 704.2mAh g-1, the pure ZnFe2O4 is only 121.7 mAh g-1, far lower than the composite. Even at the high current density of 800mAg-1, the capacity of the ZnFe2O4-graphene nanocomposite can be maintained at 271.8mAh g-1, much higher than the capacity of pure ZnFe2O4 (26.6mAh g-1). The better electrochemical performance of the material may be mainly The good conductivity of graphene and the synergistic effect between ZnFe2O4 and graphene.
【学位授予单位】：浙江师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

【共引文献】