本文選題：氟化石墨 + 石墨烯　； 參考：《蘭州理工大學(xué)》2017年碩士論文

【摘要】：石墨烯是一種由單層碳原子緊密排列成二維蜂窩狀結(jié)構(gòu)的碳材料。石墨烯展現(xiàn)出很多優(yōu)異的物理化學(xué)性能,從發(fā)現(xiàn)開始就受到各個領(lǐng)域的廣泛關(guān)注。然而,石墨烯仍然存在一些不足。例如,石墨烯片層易發(fā)生團(tuán)聚,采用化學(xué)剝離法制備的石墨烯缺陷多。此外,石墨烯是一種能帶隙為零的半導(dǎo)體,一定程度上限制了石墨烯應(yīng)用于電學(xué)器件。研究表明,通過化學(xué)摻雜可以有效調(diào)節(jié)石墨烯的電子結(jié)構(gòu),改善其物理化學(xué)性質(zhì)�；谝陨蠁栴},本論文采用石墨以及氟化石墨為原料,通過不同方法制備石墨烯及摻雜石墨烯,考察所得石墨烯及摻雜石墨烯的形貌、結(jié)構(gòu)、電導(dǎo)率及電化學(xué)性能。主要研究內(nèi)容包括以下幾個方面:(1)以石墨為原料,通過三種不同的氧化方法制備氧化石墨烯(Graphene O xide,GO),以水合肼為還原劑將GO還原為石墨烯,考察GO氧化程度對石墨烯在有機(jī)溶劑中分散性能及電化學(xué)性能的影響。結(jié)果表明,調(diào)控氧化劑的用量和種類,可以改變GO的氧化程度;以氧化程度最高的GO還原所得的石墨烯,在有機(jī)溶劑中的分散性能最好,電化學(xué)性能最佳。(2)化學(xué)剝離法是以石墨為原料,通過氧化和還原過程制備石墨烯,由于存在過度氧化以及不徹底還原,所得石墨烯存在較多的結(jié)構(gòu)缺陷,進(jìn)而影響石墨烯的性能。因此,選用氟化石墨為原料,通過超聲法,靜置法以及加熱回流法三種方法制備石墨烯,對所得石墨烯進(jìn)行形貌、結(jié)構(gòu)表征及電化學(xué)性能測試。結(jié)果表明,三種方法均可制備出單晶結(jié)構(gòu)的石墨烯,其中加熱回流法制備的石墨烯晶體有序度最高,電化學(xué)性能最佳。(3)以氟化石墨為原料,尿素為氮源,通過高溫固相反應(yīng)制備氮摻雜石墨烯(N-Gr),探討了反應(yīng)溫度對N-Gr的結(jié)構(gòu)及電化學(xué)性能的影響。結(jié)果表明,氮元素以吡咯氮、吡啶氮和石墨化氮三種形式摻入石墨烯晶格結(jié)構(gòu)中。500℃下制備的N-Gr具有最佳的電化學(xué)性能,此外,其電導(dǎo)率可達(dá)9475 S/m,遠(yuǎn)遠(yuǎn)大于以GO為原料在相同條件下制備的氮摻雜石墨烯(N-RGO)的電導(dǎo)率(200 S/m)。(4)以氟化石墨為原料,Na HSO3、Na2S2O3·5H2O、Na2SO3以及N a2S·9H2O為硫源,采用高溫固相反應(yīng)制備硫摻雜石墨烯(S-Gr),探討不同硫源對S-Gr的結(jié)構(gòu)及電化學(xué)性能影響。結(jié)果表明,硫元素以C-S-C、C-SOx-C兩種結(jié)構(gòu)摻雜進(jìn)入石墨烯晶格結(jié)構(gòu)中。其中以Na2S·9H2O作為摻雜劑制備的硫摻雜石墨烯的硫含量最高(3.35%),電導(dǎo)率最高(21720 S/m),電化學(xué)性能最佳。
[Abstract]:Graphene is a kind of carbon material which consists of a single layer of carbon atoms tightly arranged into two-dimensional honeycomb structure. Graphene shows many excellent physical and chemical properties, and has attracted wide attention from the beginning of its discovery. However, there are still some deficiencies in graphene. For example, graphene laminates are easy to be agglomerated, and many graphene defects are produced by chemical stripping method. In addition, graphene is a kind of semiconductor with zero band gap, which limits the application of graphene to electrical devices to some extent. The results show that the electronic structure of graphene can be adjusted and its physical and chemical properties can be improved by chemical doping. Based on the above problems, graphene and graphene doped with graphite and graphite fluoride were prepared by different methods. The morphology, structure, conductivity and electrochemical properties of graphene and doped graphene were investigated. The main research contents include the following aspects: (1) Graphene oxide O xidegol was prepared by three different oxidation methods using graphite as raw material, and go was reduced to graphene by hydrazine hydrate. The effects of go oxidation degree on the dispersion and electrochemical properties of graphene in organic solvents were investigated. The results showed that the oxidation degree of go could be changed by adjusting the amount and type of oxidant, and the graphene reduced by go with the highest degree of oxidation had the best dispersion in organic solvent. The method of chemical stripping is to prepare graphene from graphite by oxidation and reduction. Because of excessive oxidation and incomplete reduction, there are many structural defects in the obtained graphene. Furthermore, the properties of graphene are affected. Therefore, graphite fluoride was used as raw material to prepare graphene by ultrasonic method, static method and heating reflux method. The morphology, structure and electrochemical properties of the obtained graphene were characterized. The results showed that graphene with single crystal structure could be prepared by the three methods. Among them, the order degree of graphene prepared by heating reflux method was the highest, and the electrochemical performance of graphene was the best. The graphite fluoride was used as raw material and urea as nitrogen source. N-doped graphene N-Gr-O was prepared by solid state reaction at high temperature. The effect of reaction temperature on the structure and electrochemical properties of N-Gr was investigated. The results show that the N-Gr doped with pyrrole nitrogen, pyridine nitrogen and graphitized nitrogen into graphene lattice structure at .500 鈩，

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