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摘要进入21世纪，能源问题日渐突出，如何获得可再生新能源，是人类社会持续发展进步的前提保证。由于来源广泛、热值高和燃烧产物无污染，氢能是一种很有前景的新能源。然而，氢能的应用需要解决一些关键性的问题：一方面，常温常压下可逆储氢材料的获得是氢能利用的关键；另一方面， 在工业制氢中如何实现制得的氢气与其它杂质气体分子有效分离，也是一个很重要的问题。本文介绍了用Materials Studio 建立氮和硼取代多孔石墨烯和利用多孔石墨烯卷曲成的多孔碳纳米管结构，并采用基于第一性原理的 VASP 软件包对相关结构进行优化，找到多孔石墨烯在不同掺氮和掺硼浓度下的最优化晶格常数和各种多孔碳纳米管的最优结构。在此基础上，计算了氢气分子相对于甲烷、一氧化碳和二氧化碳等分子对于氮和硼掺杂的多孔石墨烯的透过率比；研究了由多孔石墨烯卷曲而成的4种衍生单壁多孔纳米管(6, 6),(9, 0),(12, 0)和(9, 9)等的能带带隙和2种衍生单壁多孔纳米管(6, 6)和(12, 0)的储氢性能。结果表明，用氮和硼元素对多孔石墨烯进行掺杂可以提高氢气分子相对于甲烷、一氧化碳和二氧化碳等分子的透过率比，从而可以获得更为理想的氢气提纯材料；而对于单壁多孔纳米管(6, 6)和(12, 0)，在用轻金属Ca修饰后，具有比多孔石墨烯更好的储氢性能，这说明利用多孔碳纳米管的卷曲效应，可以改善多孔石墨烯的储氢性能，从而获得更为理想的储氢材料。9918
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关键词 多孔石墨烯 氢气吸附 氮硼取代 锂钙掺杂 第一性原理 选择性透过 氢气提纯 卷曲效应
毕业设计说明书（论文）外文摘要
Title Properties of Porous Graphene Derivatives: A First-Principle Study
Abstract
One urgent issue in the 21st century is the energy crisis. To find renewable energy plays a key role in the life of human being. With its abundance, high efficiency and environmentally friendly merit, hydrogen is a suitable substitution for traditional fossil energy. The nitrogen and boron substituted porous graphene (PG) and porous nanotube structures derived from curved PG are established with the Materials Studio software and optimized using VASP package. We have obtained the optimized lattice constant of nitrogen-doped PG with different doping concentration. Based on these structures, on one hand, we compared the relative ability of hydrogen molecules passing through the B and N doped PG membrane with those of methane, carbon monoxide and carbon dioxide molecules. On the other hand, we calculated the band structures of four PG derivatives, namely (6, 6), (9, 0), (12, 0) and (9, 9) single-walled porous nanotubes and the hydrogen adsorption properties of (6, 6) and (12, 0) single-walled porous nanotubes. It is evident in our results that nitrogen and boron substitutions can greatly improve the hydrogen purification of the porous structure, in comparison with the pristine PG. Besides, the (6, 6) and (12, 0) single-walled porous nanotubes can yield more desirable hydrogen storage property by decorating with calcium atom, compared to that of the pristine PG. This suggests that the curve effect of porous nanotube is beneficial to high hydrogen uptake.
Keywords porous graphene nitrogen and boron substitution
selective permeability hydrogen storage lithium and calcium doping
hydrogen purification curvature effect first principle calculations
目 录
1 引言 1
2 理论背景2