石墨烯的制备及其作为电极的典型应用

1、第42卷第5期 当 代 化 工 Vol.42,No.5 2013年5月 Contemporary Chemical Industry May,2013 收稿日期:2013-03-08 作者简介:郝翊彤(1993-,女,黑龙江林甸人,研究方向:控制工程。E-mail:hytviolin。石墨烯的制备及其作为电极的典型应用郝翊彤1,贾 伟2(1. 中国石油大学(北京化学工程学院,北京 102249; 2. 中国石油抚顺石化公司,辽宁 抚顺 113000摘 要:石墨烯是目前发现的唯一存在于室温条件下的二维自由态原子晶体,它具有非常优秀的电学、光学及机械性能,同时还具有非常好的热学稳定性、化学稳定性。

2、本文主要介绍了石墨烯导电薄膜的几种主要制备方法以及石墨烯导电薄膜作为电极应用在各个领域如:液晶显示领域、光伏领域、超级电容器及LED 显示器件方面的研究进展,并对石墨烯电极的制备及应用进行了展望。 关 键 词:石墨烯;石墨烯制备;石墨烯应用中图分类号:O 74 文献标识码: A 文章编号: 1671-0460(201305-0620-04Preparation of Graphene and Its Typical Application as an ElectrodeHAO Yu-tong 1,JIA Wei 2(1. College of Chemical Engineering ,Chi

3、na University of Petroleum, Beijing 102249,China ;2. PetroChina Fushun Ptrochemical Company, Liaoning Fushun 113000,China Abstract : At present, graphene is the unique atomic crystal in two-dimensional free state that has been found. It has excellent electrical, optical and mechanical properties. Me

4、anwhile,it also has great thermal and chemical stability. In this paper, several main preparation methods of graphene conductive thin film were introduced as well as research progress in application of graphene conductive thin film as an electrode, such as liquid crystal display (LCD industry, photo

5、voltaic industry, super capacitor industry and so on. At last, application prospect of the graphene electrode was put forward.Key words : Graphene; Application; Preparation石墨烯是碳的一种单质,与金刚石、石墨等同为碳的同素异形体。石墨烯具有完美的二维结构,2004年之前的研究普遍认为,由于热力学涨落,二维晶体在有限温度下不可能自由存在,但2004年,英国Manchester 大学的两位科学家Andre Geim 和Konst

6、antin Novoselov 采用普通胶带从高温裂解石墨上反复剥离第一次获得了石墨烯1,打破了“二维晶体在有限温度下不可能自由存在”的论断,两人因此获得了2010年诺贝尔物理学奖,从此揭开了石墨烯研究的热潮。2004 年之后,关于石墨烯的研究报道如雨后春笋般涌现,在Science、Nature 上相关报道就有400余篇2。石墨烯具有良好的电学、力学、热学及光学特性。石墨烯的载流子可以是电子也可以是空穴,其迁移率可高达1×105 cm 2V -1s -13,任何一种金属材料都达不到这么高的迁移率,而且其载流子的速度高于其他所有材料,高达106 m/s,为光速的1/30004。石墨烯是

7、人类已知强度最高的物质,比金刚石还要坚硬5。石墨烯具有极高的弹性模量,高达1.1 TPa 6,同时它还是一种超轻材料。除具备良好的电学、力学、热学性能以外,石墨烯还具有良好的光学性能,单层石墨烯的透光率可达97.7%,五层石墨烯样品的透光率可达90%7。由于具备以上优秀的性能,石墨烯薄膜被广泛作为电极材料应用于各个领域。1 石墨烯的制备在上一节中提到,可以使用机械剥离法进行石墨烯的制备,但机械剥离法利用胶带反复粘贴高温裂解石墨得到大量石墨片,从中寻找石墨烯,产量极低,作为实验室研究,机械剥离法是一种简单廉价的方法,但如果作为大规模工业生产则明显不适合,故而人们开始寻找其他更高效的方法,以适应实

8、际应用的需要。制备大面积、连续性好、高质量的石墨烯薄膜具有重要的意义。本节将目前主要的制备石墨烯的方法进行介绍。1.1 化学气相沉淀法(CVD 法化学气相沉淀法8-19具有成膜品质高、产量大等突出优点,此方法制备的石墨烯导电薄膜的电导率接近纯石墨的电导率,而且薄膜厚度可以通过相关的实验参数进行控制,从而实现薄膜的可控生长15,18。化学气相沉淀法制备石墨烯薄膜装置简图如图1所示。第42卷第5期 郝翊彤,等:石墨烯的制备及其作为电极的典型应用 621 图1 化学气相沉淀装置简图Fig. 1 The chemical vapor deposition apparatus 制备石墨烯薄膜电极的具体步

9、骤如下: (1碳源准备。(2将金属箔基底放入电炉的加热区中央,密封反应室。(3通入氩气,加热反应室温度至反应温度。 (4保持氩气流量不变,保温一段时间,对金属箔基底进行高温预热处理。(5开启精密流量泵,使反应溶液通过毛细管注入反应室进行反应,碳源在高温反应区中分解出碳原子并在金属基底上沉积并逐渐形成连读的石墨烯薄膜。(6反应完毕,停止进给反应溶液,将金属箔基底快速移动到炉口,关闭电炉,保持氩气流量不变,直至炉温冷却到一定温度以下。1.2 氧化还原法氧化还原法20-22成本较低,产量较大,因此被广泛采用,但使用这种方法制得的石墨烯往往存在一定缺陷,导电效果略差。氧化还原法原理如图2所示。图2 氧

10、化还原法原理图Fig. 2 The schematic diagram of the oxidation-reductionmethod氧化还原法步骤如下:(1将石墨进行氧化,对其表面进行官能团修饰,进行官能团修饰是为了降低石墨中碳原子相互之间的范德华力,从而使石墨更易溶于水21。(2将氧化石墨在水中剥离。 (3对氧化石墨烯进行还原,从而制得石墨烯。目前石墨氧化主要有三种方法:Hummers 法23、Brodie 法24和Standenmaier 法25,26,其中以Hummers 法及其改进方法因反应装置简单,生产周期短,安全性高而应用最广。得到氧化石墨烯后,由于氧化石墨烯是绝缘体,需要对其

11、进行还原以得到石墨烯,目前对石墨烯进行还原通常有三类方法:(1使用肼等还原剂对氧化石墨烯进行还原,该方法一般不需要很高的温度和压力27。但该方法往往只能对表面一层的氧化石墨烯进行还原,还原效果较差,得到的石墨烯导电性不好。(2利用高温(1 000 以上对氧化石墨烯进行退火还原28,高温退火还原氧化石墨烯得到的石墨烯质量较好,还原比较彻底,但使用该方法对实验条件要求也比较苛刻,不适合进行大范围的推广应用。(3将催化剂混合到氧化石墨烯中29,在光照或高温条件下,使氧化石墨烯还原。1.3 SiC 热分解法SiC 热分解法可获得高质量、不同重构方式、不同几何形状的石墨烯30。目前使用SiC 热分解法,

12、可以制得尺寸达4英寸的石墨烯薄膜。图3为SiC热分解法的步骤。图3 SiC 分解法过程示意图Fig. 3 SiC decomposition process diagram该方法在特定晶面上热解脱去Si 来制取石墨烯,步骤如下:(1利用O 2或H 2对样品表面进行蚀刻。(2在真空条件下利用电子轰击进行加热到 1 000 以去除表面的氧化物。(3升温至1 2501 450 ,保持恒温一段时间,即可获得石墨烯。 1.4 其他方法除以上三种主流的方法外,制取石墨烯还有许多种其他方法,例如:碳纳米管切开法31,32,使用该方法可获得大量边缘齐整、形状极其规则的优质纳米级石墨烯条带。超声分散法33,34

13、该方法工艺较为简单,制得的石墨烯质量较好,但想进一步提纯则较为困难。溶剂热法35该方法工艺简单、产量高。2 石墨烯作为薄膜电极的应用2.1 在液晶显示领域上的应用2008年,英国Manchester 的Blake 等人将石墨622 当 代 化 工 2013年5月 烯薄膜电极应用到液晶显示领域,得到了具有高对比度等优异性能的液晶元件36。图4为该元件结构简图。图4 液晶元件简图Fig. 4 Liquid crystal element sketch1-玻璃(1 mm; 2-石墨烯; 3-Cr/Au 层; 4-聚乙烯醇(40 nm; 5-液晶(20 m; 6-取向层(40 nm; 7-ITO(15

14、0 nm; 8-玻璃(1 mm2.2 在光伏领域上的应用在石墨烯出现之前,一般的材料难以作为导电材料应用于光伏产业,因为同时要求材料具有良好的透光性及导电性,而一般导电性好的材料,说明其内部电子运动较为剧烈,从而导致光(电磁波无法透过,反之如果透光性较好,则说明其内部自由电子较少,导电性则会较差。在第一节中提到,石墨烯具有良好的透光性能,同时具有极佳的导电性能,目前石墨烯被广泛应用于光伏产业。2010年,麻省理工学院的Park 等利用CVD 法制备的石墨烯薄膜被用作有机光伏器件的透明电极37。图5该太阳能电池的结构图。图5 使用石墨烯电极的太阳能电池结构图 Fig. 5 Structure o

15、f solar cell using graphene electrode研究表明,该太阳能电池转化率可达1.63%,照采取传统电极的太阳能电池1.77%已较为接近。另外需要注意的一点是,传统的太阳能电池采用的电极材料中需要稀土金属铟(In,而石墨烯却通过各种常见原料大量制取。2.3 在超级电容器上的应用超级电容器是一类高比表面积碳材料、金属氧化物和导电聚合物等电极材料的新型的储能装置。具有充电时间短、循环寿命长、功率密度高、温度特性好等特点。提高超级电容器的性能就需要提高电极材料的比电容密度和电容器的额定电压,同时降低电容器的等效电阻。图8为超级电容器的功率密度和能量密度与其他储能装置的对比

16、。通过图6可以发现,超级电容器性能明显优于其他储能装置。2008年,美国德克萨斯大学奥斯汀分校的Meryl D 等利用氧化还原法制得石墨烯并将其制成超级电容器,该电容器测试模型在水中和有机电解质中的比电容密度分别为135 pF/g 和99pF/g 39。图6 各种储能装置功率密度和能量密度对比38Fig. 6 Contrast of a variety of energy storage devices powerdensity and energy density2.4 在LED 器件上的应用将石墨烯薄膜电极引入LED 器件可以改善电极的透光特性,降低电阻,提高器件的可靠性。目前世界各国研究

17、人员对石墨烯在有机材料LED 40、宽禁带无机半导体材料LED 41、纳米阵列LED 42、LED 器件在不同衬底上的转移43以及LED 大规模集成44等方面的应用进行了较为深入的研究。3 结束语石墨烯的具有极好的导电性能、透光性能、机械性能及多种优良的性质。然而,要想使石墨烯真正的被广泛推广使用,必须能够得到大面积、高质量的石墨烯。本文就石墨烯的性质和几种主要的制备方法进行了简介,目前已可以制得较大面积,质量较好的石墨烯,但仍然有许多问题尚待解决,另外在工艺的改进和优化,以及新的更高效简便的制备方法的探索上仍然有很大的发展提升空间,以求制得更大面积、质量更高的石墨烯。本文对石墨烯薄膜作为导电

18、电极的应用进行了简单介绍,相信随着石墨烯制备工艺的不断提升,石墨烯将更广泛的应用于各个领域。参考文献:1 Novoselov S, Geim K, Morozov V, et al. Electric field effect in atomically第42卷第5期 郝翊彤,等:石墨烯的制备及其作为电极的典型应用 623thin carbon filmsJ.Science, 2004, 306 (5696: 666-669.2徐秀娟,秦金贵,李振. 石墨烯研究进展J. 化学进展,2009,21(12:2559-2567.3吴洪鹏. 石墨烯的制备及在超级电容器中的应用D. 北京:北京交通大学,

19、 2012.4 Castro N, Guinea F, Peres N M R, et al. The electronic properties ofgrapheneJ.REV MOD PHYS ,2009(14:1-55.5吴洪鹏. 石墨烯的制备及在超级电容器中的应用D. 北京:北京交通大学, 2012.6 Lee C, Wei X, Kysar J W, et al. Measurement of the elastic propertiesand intrinsic strength of monolayer graphemeJ. Science, 2008,321(5887:385-

20、388.7 Nair R, Blake P, Grigorenko A, et al. Fine Structure Constant DefinesVisual Transparency of GrapheneJ. Science, 2008(320:1308.8 Li X L, Zhang G Y, Bai X D, et al. Highly conducting graphene sheetsand Langmuir-blodgett filmsJ. Nature Nanotech, 2008,3(9:538-542.9 Cai J M, Ruffieux P, Jaafar R, e

21、t al. Atomically precise bottom-upfabrication of graphene nanoribbonsJ. Nature, 2010,466(7305:470-473.10 Choucair M, Thordarson P, Stride J A. Gram-scale production ofgraphene based of solvothermal synthesis and sonicationJ. NatureNanotechnol, 2009, 4(1:30-33.11 Sutter P W, Flege J I, Sutter E A. Ep

22、itaxial graphene on rutheniumJ.Nature Matter, 2008, 7(5:406-411.12Coraux J, Ndiaye A T, Busse C, et al. Structural coherency of grapheneon Ir(111J. Nano Lett, 2008, 8(2:565-570.13 Yu Q K, Lian J, Siriponglert S, et al. Graphene segregated on Nisurfaces and transferred to insulatorsJ. Appl Phys Lett,

23、 2008,93(11:113103.14 Reina A, Jia X T, Ho J, et al. Large area,few-layer graphene films onarbitrary substrates by chemical vapor depositionJ. Nano Lett, 2009,9(1:30-35.15 Kim K S, Zhao Y, Jang H, et al. Large-scale pattern growth ofgraphene films for stretchable transparent electrodesJ.Nature, 2009

24、,457,706.16 Somani P R, Somani S P, Umeno M. Planer nano-graphenes fromcamphor by CVDJ. Chen Phys Lett, 2006, 430(1-3:56-59.17 Sun Z Z, Yan Z, Yao J, et al. Growth of graphene from solid carbonsourcesJ. Nature, 2010, 468(7323:549-552.18 Li X, Zhang G, Bai X, et al.Highly conducting graphene sheets a

25、ndlangmuir-blodgett filmsJ.Nat Nanotech, 2008( 3: 538.19 Tung V C, Allen M J, Yang Y, Kaner R B.High-throughput solutionprocessing of large-scale grapheneJ.Nat Nanotech, 2008( 4: 25. 20Pan Y, Zhang HG, Shi D X, et al. Highlyordered,millimeter-scale,continuous,single- crystalline graphenemonolayer fo

26、rmed on Ru(0001J. Adv Mater, 2009,21(27:2777-2780.21 Hirata M, Gotou T, Horiuchi S, et al. Thin-film particles of graphiteoxide I:High-yield synthesis and flexibility of the particlesJ. Carbon,2004, 42(14:2929-2937.22 Stankovich S, Piner R D, Chen X Q, et al. Stable aqueous dispersionsof graphitic n

27、anoplatelets via the reduction of exfoliated graphiteoxide in the presence of poly(sodium 4-styrenesulfonateJ. J MaterChem, 2006, 16(2:155-158.23 Hummers S,Offeman E. Preparation of graphitic oxideJ. J Am ChemSoc,1958,80(6:1339. 24Tang H, Wang Y, Li M,et al. Preparation,Structure,andElectrochemical

28、Properties of Reduced Graphene Sheet FilmsJ. AdvFunt Mater, 2009, 19(17:2782-2789.25 Oostinga B,Heersche B,Liu L, et al. Gate-induced insulating state inbilayer graphene devicesJ. Nat Mater, 2008, 7(2:151-157.26Ramesh P,Bhagyalakshmi S,Sampath S.Preparation andphysicochemical and electrochemical cha

29、racterization of exfoliatedgraphite oxideJ. J Colloid Interf Sci, 2004, 274(1:95-102.27 Li D,Mulle B,Gilje S, et al. Processable aqueous dispersions ofgraphene nanosheetsJ. Nature Nanotech, 2008, 3(2:101-105. 28 Stankovich S, Dikin A, Piner D, et al. Synthesis of graphene-basednanosheets via chemica

30、l reduction of exfoliated graphite oxideJ.Carbon, 2007, 45(7:1558-1565.29 Williams G, Seger B, Kamat V.TiO2-graphene nanocomposites,UV-assisted photocatalytic reduction of graphene oxideJ. ACS Nano.2008, 2(7:1487-1491.30E. Rollingsa, G. Gweona, S. Y. Zhoua, et al. Synthesis andcharacterization of at

31、omically thin graphite films on a silicon carbidesubstrateJ. Journal of Physics and Chemistry of Solids, 2006, 67:2172-2177.31 Li D, Muller M B, Gilje S, et al. Processable aqueous dispersions ofgrapheme nanosheetsJ. Nature Nanotech, 2008, 3(2:101-105. 32 Dikin D A, Stankovich S, Zimney E J, et al.

32、Preparation andcharacterization of grapheneoxide paperJ. Nature, 2007,448(7152:457-460.33Stankovich S, Dikin D A, Piner R D, et al. Synthesis ofgraphene-based nanosheets viaChemical reduction of exfoliatedgraphite oxideJ. Carbon, 2007, 45(7:1558-1565.34 Kosynkin D V, Higginbotham A L, Sinitskii A, e

33、t al. Longitudinalunzipping of carbonnanotubes to from graphene nanoribbonsJ.Nature, 2009, 458(7240:872-876.35 Hernandze Y, Nicolosi V, Lotya M, et al. High-yield production ofgraphene by liquid-phase exfoliation of graphite. Nature Nanotech,2008, 3(9:563-568.36 Blake P, Brimicombe P D, Nair R R, et

34、 al. Graphene-based liquidcrystal deviceJ. Nano Lett, 2008, 8(6: 1704-1708.37 Park H, Rowehl J A, Kim K K, et al. Doped grapheme electrodes fororganic solar cellsJ. Nanotechnology, 2010, 21: 505204.38 Simon P, Gogotsi Y. Materials for electrochemical capacitorsJ. NatMater, 2008, 7(11:845-854.39 Stol

35、ler D, Park J, Zhu W, et al. Graphene-Based UltracapacitorsJ.Nano Lett, 2008, 8(10:3498-3502.40Wu J, Agrawal M, Becerril H A, et al. Organic light-emitting diodes onsolution-processed grapheme transparent electrodesJ. ACS Nano,2010, 4(1:43-48.41 Kim B J, Mastro M A, Hite J, et al. Transparent conduc

36、tive graphemeelectrode in GaN-based ultra-violet light emitting diodesJ. OpticsExpress, 2010, 18(22: 23030-23034.42 Lee J M, Choung J W, Yi J, et al. Vertical pillar-superlatice array andgrapheme hybrid light emitting diodesJ. Nano lett, 2010, 10:2783-2788.43 Chung K, Lee C H, Yi G C. Transferable G

37、aN layers grown onZn-O-coated grapheme layers for optoelectronic devicesJ. Science,2010, 330(29: 655-657.44 Jo G, Choe M, Cho C Y, et al. Large-scale patterned multi-layergrapheme films as transparent conducting electrodes for GaNlight-emitting diodesJ. Nanotechnology, 2010, 21: 175201. 石墨烯的制备及其作为电极

38、的典型应用作者:郝翊彤, 贾伟, HAO Yu-tong, JIA Wei作者单位:郝翊彤,HAO Yu-tong(中国石油大学 北京化学工程学院,北京,102249, 贾伟,JIA Wei(中国石油抚顺石化公司,辽宁 抚顺,113000刊名:当代化工英文刊名:Contemporary Chemical Industry年,卷(期:2013(5参考文献(44条1.Novoselov S;Geim K;Morozov V Electric field effect in atomically thin carbon films 2004(56962.徐秀娟;秦金贵;李振石墨烯研究进展期刊论文-H

39、化学进展 2009(123.吴洪鹏石墨烯的制备及在超级电容器中的应用 20124.Castro N;Guinea F;Peres N M R The electronic properties of graphene 2009(145.吴洪鹏石墨烯的制备及在超级电容器中的应用 20126.Lee C;Wei X;Kysar J W Measurement of the elastic properties and intrinsic strength of monolayer grapheme 2008(58877.Nair R;Blake P;Grigorenko A Fine Struct

40、ure Constant Defines Visual Transparency of Graphene 2008(3208.Li X L;Zhang G Y;Bai X D Highly conducting graphene sheets and Langmuir-blodgett films 2008(099.Cai J M;Ruffieux P;Jaafar R Atomically precise bottom-up fabrication of graphene nanoribbons 2010(730510.Choucair M;Thordarson P;Stride J A G

41、ram-scale production of graphene based of solvothermal synthesis and sonication 2009(0111.Sutter P W;Flege J I;Sutter E A Epitaxial graphene on ruthenium 2008(0512.Coraux J;Ndiaye A T;Busse C Structural coherency of graphene on Ir(111 2008(0213.Yu Q K;Lian J;Siriponglert S Graphene segregated on Ni

42、surfaces and transferred to insulators 2008(1114.Reina A;Jia X T;Ho J Large area,few-layer graphene films on arbitrary substrates by chemical vapor deposition2009(0115.Kim K S;Zhao Y;Jang H Large-scale pattern growth of graphene films for stretchable transparent electrodes外文期刊 2009(723016.Somani P R

43、;Somani S P;Umeno M Planer nano-graphenes from camphor by CVD 2006(1-317.Sun Z Z;Yan Z;Yao J Growth of graphene from solid carbon sources 2010(732318.Li X;Zhang G;Bai X Highly conducting graphene sheets and langmuir-blodgett films 2008(0319.Tung V C;Allen M J;Yang Y;Kaner R B High-throughput solutio

44、n processing of large-scale graphene 2008(0420.Pan Y;Zhang HG;Shi D X Highly ordered,millimeter-scale,continuous,single-'crystalline graphene monolayer formed on Ru(0001 2009(2721.Hirata M;Gotou T;Horiuchi S Thin-film particles of graphite oxide I:High-yield synthesis and flexibility of the part

45、icles 2004(1422.Stankovich S;Piner R D;Chen X Q Stable aqueous dispersions of graphitic nanoplatelets via the reduction ofexfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate 2006(0223.Hummers S;Offeman E Preparation of graphitic oxide 1958(0624.Tang H;Wang Y;Li M Preparation,

46、Structure,and Electrochemical Properties of Reduced Graphene Sheet Films 2009(1725.Oostinga B;Heersche B;Liu L Gate-induced insulating state in bilayer graphene devices 2008(0226.Ramesh P;Bhagyalakshmi S;Sampath S Preparation and physicochemical and electrochemical characterization ofexfoliated grap

47、hite oxide 2004(0127.Li D;Mulle B;Gilje S Processable aqueous dispersions of graphene nanosheets 2008(0228.Stankovich S;Dikin A;Piner D Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide外文期刊 2007(0729.Williams G;Seger B;Kamat V TiO2-graphene nanocomposites,UV-assisted photocatalytic reduction of graphene oxide2008(07 30.E. Rollingsa;G. Gweona;S. Y. Zhoua Synthesis and characterizat