静电纺丝法制备低维纳米结构及其催化产氢方面的研究

发布时间：2018-03-03 01:21

本文选题：静电纺丝　切入点：NiO　出处：《中国科学技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着纳米科技的发展,一维纳米结构由于其独特的光电性能而被应用于多个领域,而其中,静电纺丝技术由于其装置简单,造价便宜,可变性强,可操控性强等优点,成为制备一维纳米结构的常用方法。另一方面,化石燃料不可再生及其所带来的环境污染,使得清洁能源成为当今社会的研究热点。而催化水产氢,特别是光催化水产氢,由于其产物无污染、成本低、可再生的优点更是成为当今科研界研究的重中之重。半导体催化剂由于其可以通过改变成分组成或者表面形态而提高其性能以及其量多易得,因此在洁净能源和低投入能换材料中具有重要位置。而静电纺丝制备的一维材料具有比表面积高、微结构可调等优点,可以良好的应用于催化制氢领域。目前,静电纺丝技术与催化制氢领域的结合已经引起了众多科学家的关注。本论文主要利用静电纺丝技术制备金属氧化物半导体纳米线,并围绕其形貌、结构、催化性能等方面进行了一系列研究工作,通过半导体催化剂的表面结构和比表面积对产氢性能的影响,探索静电纺丝技术在催化产氢方面的应用方向。本论文取得的主要成果如下： (1)发现了样品表面暴露的高能面原子密度对催化活性的影响。静电纺丝技术制备的NiO纳米线,经过非平衡态煅烧,样品颗粒表面具有大量的表面台阶,这使得高能面能够保留下来,并最终导致其暴露的高指数面原子密度较大。并且,样品的催化特性与其暴露的高指数面原子密度成正相关关系,当样品量为NiO30%,负载量为2wt%时,暴露的高指数面原子密度最大(2.92×107/cm)电催化和光催化性能(150mmol·g-1·h-1)也最好。这种结合静电纺丝技术和热处理,调节样品表面结构,提高催化活性的方法,为以后低成本半导体催化制氢的发展提供了新的方向。 (2)结合静电纺丝技术和水热法,变二维MoS2纳米片为一维MoS2/Ti02复合纳米线,其比表面积得到提高,光催化活性大大增加。先通过静电纺丝技术制备Ti02纳米线,再通过水热法制备MoS2/TiO2复合结构,结果发现,Ti02纳米线周围包裹的MoS2纳米片较少(5-7层),提高了MoS2的比表面积(66m2/g)和光催化活性(16.7mmol·h-1·g-1)。这种方法为克服其他催化剂活性不高的难题提供了新的思路。
[Abstract]:With the development of nanotechnology, one-dimensional nanostructures have been used in many fields because of their unique photoelectric properties. Among them, electrostatic spinning technology has the advantages of simple device, cheap cost, strong variability, strong maneuverability and so on. On the other hand, the non-renewable fossil fuels and their environmental pollution have made clean energy a hot spot in our society. Catalytic aquatic hydrogen, especially photocatalytic hydrogen, has become a common method of preparing one-dimensional nanostructures. Because its products are pollution-free and low-cost, the advantages of being renewable have become a top priority in the field of scientific research today. Semiconductor catalysts can improve their performance and quantity by changing their composition or surface morphology. Therefore, it has an important position in clean energy and low input energy exchange materials. The one-dimensional materials prepared by electrostatic spinning have the advantages of high specific surface area and adjustable microstructure, so they can be used in the field of catalytic hydrogen production. The combination of electrostatic spinning and catalytic hydrogen production has attracted the attention of many scientists. In this paper, metal oxide semiconductor nanowires were prepared by electrospinning technology, and a series of research work was carried out around their morphology, structure, catalytic performance and so on. Through the influence of surface structure and specific surface area of semiconductor catalyst on hydrogen production performance, the application direction of electrostatic spinning technology in catalytic hydrogen production is explored. The main achievements in this paper are as follows:. (1) the influence of high energy surface atomic density on the catalytic activity was found. The surface of NiO nanowires prepared by electrostatic spinning has a large number of surface steps after non-equilibrium calcination. This allows the high energy surface to be preserved, and eventually leads to a higher atomic density at the high exponential surface. Furthermore, the catalytic properties of the sample are positively correlated with the atomic density of the exposed high exponential surface, when the amount of the sample is NiO30 and the loading amount is 2 wt%, The electrocatalytic and photocatalytic properties of the exposed high exponent surface atom density of 2.92 脳 10 ~ 7 / cm ~ (-1) are also the best. This method combines electrostatic spinning and heat treatment to adjust the surface structure of the sample and improve its catalytic activity. It provides a new direction for the development of low cost semiconductor catalytic hydrogen production. In combination with electrostatic spinning and hydrothermal method, the specific surface area and photocatalytic activity of two-dimensional MoS2 nanowires were improved, and the photocatalytic activity of Ti02 nanowires was greatly increased. The MoS2/TiO2 composite structure was prepared by hydrothermal method. The results show that there are less 5-7 layers of MoS2 nanoparticles wrapped around Ti02 nanowires, which improves the specific surface area of MoS2 (66 m2 / g) and photocatalytic activity of 16.7 mmol 路h -1 路g -1 路g -1. This method provides a new way to overcome the difficulty of other catalysts with low activity.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2;O643.36

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