碳纳米管吸附腺嘌呤及硼氮共掺的第一性原理研究

发布时间：2018-08-13 17:04

【摘要】：碳纳米管作为新时代的纳米材料,具有很多优点：比如大的比表面积、强度高、韧性好等。这些优良的物理和化学性质在物理学界、化学界、甚至材料学界都引起了广泛地关注。无论是实验上还是理论上,科学家们都不断进行的研究,结果表明,碳纳米管等纳米材料在电子器件、生物传感器、建筑材料等很多方面均占用重要地位。本文根据当前已经进行的研究进展情况,对碳纳米管的掺杂和吸附进行了研究。掺杂方面,本文采用LDA/6-21G方法进行几何结构的优化,HSE06/6-31G(?)进行能带结构的计算。吸附方面,采用LSDA、PBE、HSE06、B97D、wb97XD五种方法进行几何结构的优化,HSE06/6-31G(?)进行能带结构的计算。同一种手性的氮化硼纳米管进行对比分析,对比量选取：键长、键角、晶格常数、纳米管直径、态密度、能隙、掺杂浓度、形成能等参数。理论计算结果表明：掺杂方面,三种手性的碳纳米管的几何结构和电子结构均受到了影响,碳纳米管的键长、键角最大值变大,最小值变小,晶格常数变大；随着硼氮掺杂数量得增多,螺旋型和扶手椅型纳米管的禁带宽度变大,但对锯齿型碳纳米管的禁带宽度影响不大；掺杂后,态密度图中都在费米能级附近出现了杂质峰；随着掺杂数量的增多,体系的形成能呈线性增长。吸附方面,吸附了腺嘌呤分子后,三种手性的碳纳米管的结构变化不大,利用五种方法计算相同模型时,会出现小范围的数值波动,在计算禁带宽度时,ωB97XD计算出的结果与其他四种方法计算的结果相差较大。碳纳米管在新型纳米材料方面具有巨大的潜在应用价值,碳纳米管因其独特的性质,在将来会有更广阔的应用前景。希望我们的理论计算结果能对以后的碳纳米管掺杂及吸附方面奠定一定的基础,特别是碳纳米管吸附DNA和蛋白质这样在生物医学上具有实际应用的方面,提供一些可靠的理论依据。
[Abstract]:Carbon nanotubes (CNTs) have many advantages, such as large specific surface area, high strength, good toughness and so on. These excellent physical and chemical properties have attracted wide attention in the field of physics, chemistry and even materials. Both experimental and theoretical studies have been carried out by scientists. The results show that carbon nanotubes and other nanomaterials play an important role in many aspects such as electronic devices, biosensors, building materials and so on. In this paper, the doping and adsorption of carbon nanotubes (CNTs) have been studied according to the research progress. In the aspect of doping, LDA/6-21G method is used to optimize the geometric structure of HSE 06 / 6-31G (?) The band structure is calculated. In the aspect of adsorption, the geometric structure of HSE06 / 6-31G (?) was optimized by using five methods of LSDA-PBE06-HSE06-B97D- wb97XD. The band structure is calculated. The same chiral boron nitride nanotubes were compared and analyzed with the following parameters: bond length, bond angle, lattice constant, diameter of nanotubes, density of states, energy gap, doping concentration, formation energy and so on. The theoretical calculation results show that the geometric and electronic structures of the three chiral CNTs are affected by doping. The bond length, the maximum bond angle, the minimum value and the lattice constant of the three chiral CNTs are increased. With the increase of boron nitrogen doping amount, the band gap of spiral and armchair nanotubes becomes larger, but it has little effect on the band gap of sawtooth carbon nanotubes, and the impurity peaks appear in the density diagram of states near Fermi level after doping. With the increase of doping amount, the formation energy of the system increases linearly. On the adsorption side, the structure of the three chiral carbon nanotubes has little change after the adsorption of adenine molecules. When the same model is calculated by five different methods, there will be a small range of numerical fluctuations. In the calculation of bandgap, the calculated results of 蠅 B97XD are quite different from those of the other four methods. Carbon nanotubes (CNTs) have great potential application value in new nano-materials. Because of their unique properties, carbon nanotubes will have a wider application prospect in the future. It is hoped that our theoretical results will lay a foundation for future carbon nanotubes doping and adsorption, especially in biomedical applications such as carbon nanotubes adsorption of DNA and protein. To provide some reliable theoretical basis.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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