层状二维材料的化学气相生长及应用

发布时间：2018-03-17 05:26

本文选题：化学气相沉积　切入点：化学气相输运　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：由于在电学、光学、机械以及催化方面具有优异的性能,二维材料近年来受到了广泛的关注,其中高质量二维材料的可控生长是实现其众多潜在应用的基础。化学气法是当前国际上普遍使用的快速低成本的纳米材料合成方法。本论文选取化学气相沉积(Chemical Vapor Deposition,CVD)和化学气相输运(Chemical Vapor Transport,CVT)为合成手段,初步探索了以石墨烯和三元FePS3为代表的层状二维材料的化学气相可控合成、性能表征及其催化应用研究,主要内容包括以下两个方面:1.高质量石墨烯的CVD生长及其电输运性能的研究:对比传统的铜和铜镍基底,我们设计了一种新型的三元Cu2NiZn合金基底,通过低压CVD手段,利用液态环己烷(C6H6)在合金基底上成功地生长出具有优异电学性能的大面积单层石墨烯,并结合密度泛函理论计算解释了合金生长机制:选取甲烷(CH4)为气态碳源,我们通过常压CVD手段,在传统的铜基底上可控地生长出不同尺寸的石墨烯,并利用扫描隧道显微镜研究了晶界对其电学性能的影响,初步建立了电学性能和石墨烯尺寸之间的联系。2.高质量三元FePS3单晶的CVT生长及其OER性能的研究:利用CVT方法,通过调控Fe、P、S的单质的化学计量比以及生长温差、时间,我们成功地获得了具有高度结晶性的FePS3单晶,并利用后续球磨工艺将其剥离成具有优异电催化产氧性能(OER)的寡层FePS3纳米片。结合第一性原理计算,我们发现球磨前后FePS3的费米面附近的态密度发生了很大的变化,球磨过程中产生了很多空穴,有利于催化活性位点的充分暴露,从而解释了其电化学产氧效率提高的原因。
[Abstract]:Due to their excellent electrical, optical, mechanical and catalytic properties, two-dimensional materials have attracted extensive attention in recent years. The controllable growth of high quality two-dimensional materials is the basis of its many potential applications. Chemical gas method is a fast and low cost synthesis method of nanomaterials widely used in the world. Chemical vapor deposition (CVD) is selected in this paper. Chemical Vapor Transport (Vapor) and Chemical Vapor Transport (CVI). The chemical vapor controlled synthesis, performance characterization and catalytic application of layered two-dimensional materials, represented by graphene and ternary FePS3, were preliminarily explored. The main contents include the following two aspects: 1. Study on CVD growth and electrical transport properties of high quality graphene: a novel ternary Cu2NiZn alloy substrate was designed by low pressure CVD for copper and copper nickel substrates. A large area graphene monolayer with excellent electrical properties was successfully grown on the alloy substrate by liquid cyclohexane C6H6. The growth mechanism of the alloy was explained by density functional theory (DFT). The methane CH4 was selected as the gaseous carbon source. Graphene of different sizes was grown on conventional copper substrates by atmospheric pressure CVD, and the effect of grain boundary on its electrical properties was studied by scanning tunneling microscope (SEM). The relationship between electrical properties and graphene size was preliminarily established. 2. The CVT growth and OER properties of high quality ternary FePS3 single crystals were studied. By means of CVT method, the stoichiometric ratio, growth temperature difference and time of growth were regulated. We have successfully obtained highly crystallized FePS3 single crystals, and have been peeled off into oligodeoxygen-rich FePS3 nanocrystals with excellent electrocatalytic oxygen-producing properties by means of the following ball milling process. We found that the density of states near Fermi surface of FePS3 changed greatly before and after ball milling, and a lot of holes were produced in the milling process, which was beneficial to the full exposure of catalytic active sites, which explained the reason for the increase of electrochemical oxygen production efficiency.
【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】：2017
【分类号】：TB30

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