【作者】 张帆；

【导师】 岳冬梅；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2013， 硕士

【摘要】 众所周知，石墨烯自发现以来，因为其结构所带来的优异性能，例如，高的机械强度和高的载流子迁移率等都令人侧目。虽然石墨烯的性能优异，但是优质石墨烯却难以大量生产，以及因为石墨烯表面没有基团，石墨烯片间会因范德华力相互作用而使其在溶剂中易于团聚，这些特点都极大地影响了石墨烯的应用。本文采用化学还原的方法制备还原氧化石墨烯，通过与金属氧化物、导电聚合物复合，或者利用化学反应在氧化石墨上嫁接有机大分子化学对其进行改性，并对改性后的石墨烯纳米复合物进行详细的表征及性能的研究。主要工作如下：1、将氧化石墨先通过氯化亚砜和N,N-二甲基甲酰胺进行酰氯化，再通过鸟嘌呤上的-NH₂与酰氯化后的氯化氧化石墨反应，完成对氧化石墨的化学改性，产物命名为GMG。通过对GMG组成、结构等分析，采用透射电子显微镜、原子力显微镜、傅里叶转变红外光谱、拉曼光谱、X-射线光电子能谱、热重分析、紫外可见光谱等分析方法，以便确定产物正如预期通过共价键的方式嫁接到了氧化石墨上，并发现GMG在有机溶剂中的溶解性较前极大改善，也增大了其进一步应用的前景。另外，还对GMG的样品做了循环伏安测试，证明改性后，GMG的电化学性能得到了提升。2、将还原氧化石墨烯与导电聚合物聚苯胺以及过渡金属氧化物TiO₂纳米颗粒复合（简称为PTG），形成三明治结构。对PTG的组成、结构、形貌等进行了详细的表征，包括X-射线衍射、傅里叶转变红外光谱、拉曼光谱、X-射线光电子能谱、透射电子显微镜及原子力显微镜等手段，从多个方面证明了PTG的组成及三明治结构。通过氮吸附脱附等温线及孔径分布分析了PTG材料的孔结构。通过直流充/放电循环和倍率以及循环伏安法分析，研究其作为锂离子电池负极材料的电化学性质。研究表明，PTG是一个非常有前途的锂离子电池的负极材料。更多还原

【Abstract】 It is well known that since the graphene was found,its excellentperformance, such as its high mechanical strength, high carrier mobility, hasaroused great interest around the world. It can be attributed to its specialstructure. It still remains a great challenge towards the applications forgraphene, due to the low yield of high-quality graphene. Also graphene sheetsare easy to aggregate by the π-π coupling, due to the flat monolayer of carbonatoms which are arranged into a two-dimensional honeycomb lattice of carbon,which will lead to the agglomerate of graphene sheets in solvents. In thisthesis, we focus on the preperation and application study of modified graphenecomposites. First, the graphene oxide （GO） is synthesized by using a modifiedHummer’s method from graphite powder, then GO is reduced, which leads tothe generation of reduced graphene oxide （RGO）. After that, we modify RGOby some transition metal oxides and/or conducting polymer, and organicmolecules by covalent bonding manner, The structure, composition, andmorphology of the modified graphene are studied by a series of tools. We alsostudy their physicochemical properties. This thesis is divided into two parts,shown as follows: 1、We carry out the synthesis and characterization of DNA base guanine （G）covalently modified graphene （termed as GMG） hybrid nanostructures, by areaction between-NH2group of guanine and GOCl generated from SOCl₂reacted with-COOH group of GO. The hybrid GMG nanostructures arecharacterized by various characterization methods. GMG has about oneguanine group per20carbon atoms on graphene sheets based on XPS analysis.UV-vis spectroscopy of GMG shows weaker peaks certered at208and277nm,suggesting that the covalent bond between GO and guanine moiety hasperturbed the electronic state of the graphene sheets. The electrochemicalproperties of GMG studied by CV and galvanostatic charge-dischargemeasurement, which presents enhanced supercapacitive behavior comparedwith GO and long-term stability and reversibility, as well as excellentsolubility in organic solvents, allowing it to have potential applications innanoelectronics.2、 We report here the synthesis and characterization of athree-layer-structured hybrid graphene-based nanostructure consisting oftransition metal oxide TiO₂nanoparticles sandwiched between carbonaceouspolymer polyaniline （PANI） and graphene nanosheets （termed as PTG）. Thestructure, composition, and morphology of PTG are studied by variouscharacterization methods, which can demonstrate the sandwich structure ofPTG. We also carry out nitrogen isothermal adsorption/desorption curvestogether with the pore size distribution analysis of PTG. We study the electrochemical properties of PTG by using PTG as anode material in lithiumion batteries （LIBs）, which presents enhanced anode performance in LIBs. Theelectrochemical properties of PTG and pure TiO₂are further studied bymeasuring their cyclic voltammetry （CV） curves using a three-electrodesymmetric system. It is demonstrates that better capacitive behavior for PTGthan that of pure TiO₂.更多还原