【摘要】：染料敏化太陽(yáng)能電池(DSSC)由于成本低,環(huán)境友好,易于生產(chǎn),近年來(lái)作為有前途的新一代太陽(yáng)能電池受到重視。DSSC的電化學(xué)性能直接取決于對(duì)電極的性能。作為傳統(tǒng)的電極材料,鉑(Pt)納米材料被廣泛使用。然而,鉑金的高成本和有限的使用性限制了DSSC的大規(guī)模商業(yè)應(yīng)用。因此,為了代替?zhèn)鹘y(tǒng)的鉑材料,需要尋找具有較低成本,高導(dǎo)電性和優(yōu)良催化活性的新對(duì)電極材料。石墨烯作為最熱的明星材料之一,由于其獨(dú)特的平面二維結(jié)構(gòu),特殊的單原子層以及豐富的特性,引起了廣泛的關(guān)注。石墨烯材料由于其耐磨性、強(qiáng)度、耐熱性、電學(xué)性、光學(xué)性等特點(diǎn),可用于航空航天工程、物理、化學(xué)、材料、電信、計(jì)算機(jī)科學(xué)等多個(gè)領(lǐng)域。最近許多實(shí)驗(yàn)組報(bào)道了具有高電催化效率的石墨烯對(duì)電極材料的合成和應(yīng)用。本論文中,應(yīng)用密度泛函理論(DFT),對(duì)本征石墨烯和N、S摻雜的石墨烯材料的摻雜效應(yīng)和吸附行為進(jìn)行量子化學(xué)計(jì)算。計(jì)算結(jié)果對(duì)實(shí)驗(yàn)結(jié)果進(jìn)行了很好的解釋,并為有前景的電極材料的篩選和開(kāi)發(fā)提供了理論支持。主要研究結(jié)果如下:使用B3LYP方法和高斯軟件包,對(duì)本征石墨烯片段模型和N、S的摻雜石墨烯模型計(jì)算NBO(Natural Bond Orbital)原子電荷密度分布。結(jié)果表明N或S原子摻雜后產(chǎn)生了更多具有正電荷的活性位點(diǎn)。N/S共摻雜通過(guò)產(chǎn)生帶有更大的正電荷的活性位點(diǎn)而引起協(xié)同效應(yīng),從而增強(qiáng)對(duì)電極材料的電催化活性。使用PBE泛函和VASP程序,建立了對(duì)石墨烯系列材料的周期模型,詳細(xì)研究了本征石墨烯和N、S摻雜石墨烯對(duì)于I2的吸附行為。對(duì)于吸附能,吸附位點(diǎn),電荷轉(zhuǎn)移和帶結(jié)構(gòu)的計(jì)算表明,N/S共摻雜石墨烯比N或S單摻雜石墨烯具有更強(qiáng)的吸附能力。BADER電荷分析還揭示了N和S原子共摻雜的協(xié)同效應(yīng)。基于片段或周期性石墨烯系列模型,理論計(jì)算得出非常一致的結(jié)論:石墨烯中N和S原子的摻雜導(dǎo)致形成更多的活性位點(diǎn),這有助于I2的吸附。此外,N/S共摻雜產(chǎn)生協(xié)同效應(yīng),改善了石墨烯基電極材料的電化學(xué)性能。
[Abstract]:Dye-sensitized solar cell (DSSC) has attracted much attention in recent years because of its low cost, friendly environment and easy production. The electrochemical performance of DSSC is directly dependent on the performance of the opposite electrode. As a traditional electrode material, platinum (Pt) nanomaterials are widely used. However, the high cost and limited availability of platinum limit the large-scale commercial use of DSSC. Therefore, in order to replace the traditional platinum materials, it is necessary to find new opposite electrode materials with low cost, high conductivity and excellent catalytic activity. As one of the hottest star materials, graphene has attracted wide attention due to its unique planar two-dimensional structure, special monatomic layer and rich properties. Graphene materials can be used in aerospace engineering, physics, chemistry, materials, telecommunications, computer science and other fields due to its wear resistance, strength, heat resistance, electrical properties, optical properties and other characteristics. Recently, many experimental groups reported the synthesis and application of graphene electrode materials with high electrocatalytic efficiency. In this paper, the density functional theory (DFT),) is used to calculate the doping effect and adsorption behavior of graphene and Na-S doped graphene materials by quantum chemistry. The calculated results provide a good explanation for the experimental results and provide theoretical support for the screening and development of promising electrode materials. The main results are as follows: B3LYP method and Gao Si software package are used to calculate the charge density distribution of NBO (Natural Bond Orbital) atom for the intrinsic graphene fragment model and the doped graphene model. The results show that N or S atoms have more active sites with positive charge after doping. The co-doping of N / S leads to synergistic effect by producing active sites with larger positive charges, thus enhancing the electrocatalytic activity of electrode materials. Using PBE functional and VASP program, the periodic model of graphene series was established, and the adsorption behavior of I _ 2 for I _ 2 by intrinsic graphene and Na-S doped graphene was studied in detail. The calculation of adsorption energy, adsorption site, charge transfer and band structure shows that N / S co-doped graphene has a stronger adsorption ability than N or S doped graphene. The charge analysis of BADER also reveals the synergistic effect of N and S codoping. Based on the partial or periodic graphene series models, the theoretical calculations show that the doping of N and S atoms in graphene leads to the formation of more active sites, which is helpful to the adsorption of I2. In addition, the synergistic effect of N / S co-doping improves the electrochemical performance of graphene based electrode materials.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM914.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 郭浩;丁麗;劉向陽(yáng);;太陽(yáng)能電池的研究現(xiàn)狀及發(fā)展趨勢(shì)[J];許昌學(xué)院學(xué)報(bào);2006年02期

相關(guān)碩士學(xué)位論文 前3條

1 黨雪潔;石墨烯和硅烯等二維納米材料表界面的理論研究[D];蘇州大學(xué);2015年

2 張楠楠;染料敏化太陽(yáng)能電池新型對(duì)電極材料的結(jié)構(gòu)可控設(shè)計(jì)與應(yīng)用[D];華東理工大學(xué);2014年

3 牛海紅;染料敏化太陽(yáng)電池光陽(yáng)極的研究及電池性能的優(yōu)化[D];蘭州大學(xué);2011年

，

本文編號(hào)：2171093