دانلود رایگان مقاله لاتین نوع تلفیق نفوذ اکسید گرافیت از سایت الزویر
عنوان فارسی مقاله:
روش و نوع تلفیق شدت نفوذ اکسید گرافیت نتیجه خواص گرافن
عنوان انگلیسی مقاله:
Synthesis procedure and type of graphite oxide strongly influence resulting graphene properties
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Due to its unique electrical, optical and mechanical properties graphene has been intensively studied since its isolation in 2004 [1–3]. These unique properties make graphene a highly promising material for a wide range of applications in modern electronics and electrochemical power sources such as supercapacitors, fuel cells or batteries which are of extreme importance for the green energy production and storage [4–9]. Thanks to extremely high surface area, graphene also seems to be useful for removal of toxic contaminants from environment[10–12]. Anumber of various methods for the synthesis of graphene have been reported. One possibility how to obtain graphene directly is themechanical exfoliation of graphite [13], other common methods are CVD techniques [14]. CVD-based graphene layers are of large size, high-quality and they are important for optoelectronic or microelectronic devices. However, for applications in the field of electrochemical power sources and composites, graphene should be produced in larger amounts [15–17]. For this purpose, the reduction of graphite oxide seems to be the most suitablemethod.Inthismethodgraphiteprecursor is oxidizedin acidic environment using chlorate or permanganate methods to graphite oxide. Subsequently, the formed graphite oxide is reduced by different routes yielding graphene. Graphite oxide can be reduced using microwaves [18], by ion bombardment [19], or by chemical or thermal reduction [20,21]. Various reducing agents for the chemical reduction have been reported from which the most common are hydrazine and its derivatives [20], hydroquinone [22], complex hydrides [23] or nascent hydrogen [24–26]. Graphite oxide can be also reduced thermally in inert (nitrogen) or reducing atmosphere (hydrogen). The thermal reduction of graphite oxide produces graphene with the highest degree of exfoliation and also largest surface area [27,28]. The thermal reduction is usually performed by rapid heating in suitable non-oxidizing atmosphere. The mechanism of the thermal reduction has been described as a process of decomposition of oxygen containing functional groups forming carbon dioxide, carbon monoxide and water during the heating. The evolved gaseous products increase interlayer pressure, which eventually leads to the exfoliation. However, a few papers described that the process is much more complex accompanied by a release of more complex species during exfoliation [29,30]. In this study, we investigated in detail the influence of starting graphite oxide preparation method on the composition, structure and properties of thermally and chemically reduced graphene. For these syntheses we selected the methods which can be easily scaledup for industrial production using rapid thermal exfoliation in nitrogen atmosphere and chemical reduction using hydrazine in alkaline environment. For the synthesis of graphite oxides the chlorate based methods (Brodie, Staudenmaier and Hofmann method) and permanganate methods (Hummers and Tour method) were applied. Chemical composition of the obtained products was investigated in detail using X-ray photoelectron spectroscopy (XPS) and elemental combustion analysis. The structural properties were investigated by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), surface area measurement (BET method) and the thermal stability towards oxidation was probed by simultaneous thermal analysis (STA). In addition basic electrochemical properties were investigated using cyclic voltammetry and various redox probes.
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کلمات کلیدی:
Electrochemistry of Graphene and Related Materials - Chemical ... pubs.acs.org/doi/full/10.1021/cr500023c by A Ambrosi - 2014 - Cited by 327 - Related articles Jump to Preparation of Graphene and Its Properties - ... which strongly influence its properties. ... intimately embedded in the resulting graphene. Polymer-graphene Nanocomposites - Page 76 - Google Books Result https://books.google.com/books?isbn=1849735670 Vikas Mittal, Harry Kroto - 2012 - Science dealing with the preparation of electrically conductive graphene–polymer ... can strongly influence the electrical properties of the resulting nanocomposite. Graphite, Graphene, and Their Polymer Nanocomposites https://books.google.com/books?isbn=1439827796 Prithu Mukhopadhyay, Rakesh K. Gupta - 2012 - Technology & Engineering Before. answering.this.question,.let.us.begin.by.noting.that.graphene.and.CNTs.are. ... The.boundary.con- ditions.applied.when.rolling.the.sheet.strongly.influence.the.properties.of. the.obtained.CNT,.even.affecting.the.resulting.band.structure ... Electronic and Mechanical Properties of Graphene–Germanium ... pubs.acs.org/doi/full/10.1021/acs.nanolett.5b02833 by B Kiraly - 2015 - Cited by 15 - Related articles Oct 27, 2015 - Electronic and Mechanical Properties of Graphene–Germanium ... semiconducting surface, the structure and properties of the resulting material interface ... in graphene is strongly influenced by the local dielectric environment, ... Development of an Ultrafast Low-Energy Electron Diffraction Setup https://books.google.com/books?isbn=3319185616 Max Gulde - 2015 - Science Here, too, the modification of material properties is in the foreground, which is ... The resulting features make these new materials interesting for a wide range ... However, the strong physisorption of the polymer in contact with the graphene results ... Tacticity strongly influences the physical properties of a polymer, including ... Influence of parent graphite particle size on the electrochemistry of ... pubs.rsc.org/-/content/articlehtml/2012/cp/c2cp41462g by SY Chee - 2012 - Cited by 13 - Related articles Aug 8, 2012 - Electrochemical applications of graphene are of very high importance. ... size of graphite materials, influences the properties of the resulting materials. ... it is common to subject graphite to strong oxidants and acids and then ...
