石墨烯与半导体界面电子转移的研究

发布时间：2018-05-16 19:28

本文选题：复合纳米材料 + 第一性原子计算　；参考：《贵州大学》2015年硕士论文

【摘要】：近年来,石墨烯由于其特有的物理化学性质在复合材料领域受到的越来越多研究者的关注。很多研究者发现,一些包含石墨烯材料的新型复合材料所具有的性质可以突破传统复合材料性质的理论极限,所以这种新型的复合材料必将取代传统的复合材料。特别是在光催化领域,科学家们一直致力于设计新型的光催化剂来提高光催化剂的催化效率。本文构建了graphene@Cu_2O(100):Pd这样的新型复合模型,以进行了第一性原理计算为理论基础,揭示了石墨烯与半导体氧化亚铜之间的电子转移机制以及复合结构的光吸收性质,找到了制约氧化亚铜光催化性能的原因,解决了半导体光催化剂表面电子-空穴对容易复合的问题,从而提高了半导体氧化亚铜光催化的稳定性。本文的创新之处在于利用石墨烯与氧化亚铜结合,并且用Pd原子在Cu_2O(100)面进行掺杂以增强石墨烯与氧化亚铜的相互作用。本文的研究结果对于光催化领域新型复合纳米结构的研究具有重要意义。本文的第一章主要讲述了本文的研究背景、目的意义和国内外的研究现状;第二章给出了密度泛函理论以及计算方法的相关介绍;第三章研究的是Pd原子对于氧化亚铜光催化性能的影响;第四章研究的是石墨烯与氧化亚铜结合之后的新型复合结构的光催化性质;最后的第五章则是对本文研究的总结以及对今后工作的展望。基于石墨烯与氧化亚铜所形成的复合结构的光电性质的研究,我们得出了如下结论:第一,通过对不同Pd掺杂浓度的Cu_2O(100)面结构的光电性质研究,我们发现了由于Pd原子掺杂引入的新能级可以提高氧化亚铜电子-空穴对的分离能力,增加半导体的光催化效率。第二,在石墨烯结构吸附在Cu_2O(100)面上之后,石墨烯与Cu_2O(100)面形成肖特基势垒,这种势垒具有整流作用,可以有效的抑制Cu_2O(100)面上的电子-空穴对的复合,增加半导体光催化剂的稳定性。
[Abstract]:In recent years, graphene has attracted more and more attention in the field of composites due to its unique physical and chemical properties. Many researchers have found that the properties of some new composites containing graphene materials can break through the theoretical limits of the properties of traditional composite materials, so this new composite material will replace the traditional composite materials. Especially in the field of photocatalysis, scientists have been working to design new photocatalysts to improve the photocatalytic efficiency. In this paper, a new composite model such as graphene@Cu_2O(100):Pd is constructed. Based on the first-principle calculation, the electron transfer mechanism between graphene and cuprous oxide and the optical absorption properties of the composite structure are revealed. The reason of restricting the photocatalytic performance of cuprous oxide was found, and the problem of easy recombination of electron-hole pairs on semiconductor photocatalysts was solved, thus improving the stability of photocatalysis of semiconductor photocatalysts. The innovation of this paper is to combine graphene with cuprous oxide and doping PD atoms on Cu2O100) surface to enhance the interaction between graphene and cuprous oxide. The results of this paper are of great significance for the study of novel composite nanostructures in the field of photocatalysis. The first chapter of this paper mainly describes the research background, the purpose significance and the domestic and foreign research situation, the second chapter gives the density functional theory and the calculation method related introduction; In chapter 3, the effect of PD atom on the photocatalytic performance of cuprous oxide is studied, and in chapter 4, the photocatalytic properties of the new composite structure after the combination of graphene and cuprous oxide are studied. The last chapter is the summary of this paper and the prospect of future work. Based on the study of the photoelectric properties of the composite structure formed by graphene and cuprous oxide, the following conclusions are obtained: first, the photoelectric properties of Cu _ 2O _ (100) surface structure with different PD doping concentrations are studied. It is found that the new energy level introduced by PD atoms can improve the separation ability of cuprous oxide electron-hole pairs and increase the photocatalytic efficiency of semiconductors. Second, after the graphene structure is adsorbed on the surface of Cu2O100), graphene and CuS2O100) form Schottky barrier. This barrier has the function of rectifying and can effectively suppress the combination of electron-hole pairs on the Cu2O100) surface. Increase the stability of semiconductor photocatalyst.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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