Improved hole injection in bulk heterojunction bhj. Chemical oxidation of graphite to graphene oxide followed by the reduction process is the commonly used method for mass scale production of graphene or reduced graphene oxide rgo. Since graphene was first reported in 2004, made using. Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene like materials, is also discussed. Graphene oxide and reduced graphene oxide, product developments for upcoming applications. Synthesis of graphene oxide and reduced graphene oxide page 70 to exfoliate the layers figure 3. Thanks to its specific chemical and physical properties, graphene has aroused growing interest in many fields of science and technology. A number of techniques, including solid state nmr, demonstrate.
Graphene was prepared by a simple chemical reduction of graphite oxide in the dimethylacetamide dmach 2 o mixture solvent. Chemical synthesis and applications of graphene and carbon. Many different methods exist for both the oxidation and reduction steps, leading to highly variable types and amounts of metallic contaminations. Large scale production of graphene can also be effectively realized through chemical reduction of graphene oxide. Highlevel supercapacitive performance of chemically reduced. Structural evolution during the reduction of chemically. Chemical reduction of graphene oxide by a mild and nonconventional reducing agent, fecl2hcl, produces optimally healed and ambient stable reduced graphene oxide with ultrahigh performance in supercapacitor applications, whereby the reducing agent can also be recycled.
The field of nanotechnology has advanced following the discovery of a twodimensional material of sp2 hybridized carbon atoms, graphene in 2004 by geim and novoselov. Production of graphene oxide from pitchbased carbon fiber. Physical properties and device applications of graphene oxide. Synthesis, characterization, chemical reduction and. Atoms at the edges of a graphene sheet have special chemical reactivity. Graphene is the only form of carbon or solid material in which every atom is available for chemical reaction from two sides due to the 2d structure. Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure. In this paper, we propose strainsensitive thin films based on chemically reduced graphene oxide go and multiwalled carbon nanotubes mwcnts without adding any further surfactants. The preparation of reduced graphene oxide rgo by chemical reduction of. In this chapter, we discuss a variety of chemical reactions introduced for go. The artemisinin was used for the reduction of graphene oxide. Since geim and coworkers reported their groundbreaking experiments on graphene, research on graphene oxide go and its derivatives has greatly influenced the field of modern physics, chemistry, device fabrication, material science, and. This ready reference and handbook is unique in its focus on synthesis and the application of graphene and other carbon materials with an emphasis on chemistry aspects. Concomitant thionation and reduction of graphene oxide through solidgas metathetical sulfidation reactions at high temperatures.
A simple method has been used to modify the anode of hybrid solar cells by depositing these two solutionprocessable nanocarbon materials between poly3,4. Reduced graphene oxide rgo has been extensively investigated in past reports. The chemical reduction of graphene oxide is a promising route towards the large scale production of graphene for commercial applications. The debris present, roughly onethird by mass, can be removed by a base wash. Selective removal of hydroxyl groups from graphene oxide. Chemistry with graphene and graphene oxide challenges for. The chemical production of graphene as well as its controlled wet chemical modification is a challenge for synthetic chemists and the characterization of reaction products requires sophisticated analytic methods. The reduced approaches are greatly important for rgo sheets applied in electrical, optical and electrochemical fields. Applications of graphene oxide and reduced graphene oxide. Reduction, dispersity and electrical properties of. Various solutionbased chemical methods can be applied to go, which has stimulated a new research area called wet chemistry of grahene. Graphene oxide, reduced graphene oxide, graphene, carbocatalyst, oxidation, reduction. Facile synthesis of graphene via reduction of graphene oxide by.
The present study focuses on the properties of microcrystalline chitosan mcch. The reduced graphene oxide suspension in the mixture of. The main simulation and computation theories to establish these structure. Graphene has the highest ratio of edge atoms of any allotrope. Graphene is a 2d carbon material made up entirely of conjugated sp 2 carbons arranged in a honeycomb structure. Graphite oxide was prepared from natural graphite by the well known. Crossref wenjun liu, yongke wang and zhaohui li, tuning of surface wettability of rgobased aerogels for various adsorbates in water using different amino acids, chem. Currently, a number of techniques are used to produce graphene and these include epitaxial growth, chemical vapour deposition cvd, and thermal or mechanical exfoliation. A simple and efficient method to prepare graphene by. Interaction of microcrystalline chitosan with graphene. The results from fourier transform infrared spectroscopy, raman spectroscopy and xray photoelectron spectroscopy indicated that the reduction degree of graphene products increased with the increase in the volume ratio of dmac and water v dmac v h2o, and kept. The results from fourier transform infrared spectroscopy, raman spectroscopy and xray photoelectron spectroscopy indicated that the reduction degree of graphene products increased with the increase in the volume ratio of dmac and water v dmac v h2o, and. Graphene based nanomaterials and their electrochemistry. The maximally oxidized bulk product is a yellow solid with c.
A simplified chemical reduction method for preparation of. Graphene oxide go, product numbers 763705 and 777676 is a unique material that can be viewed as a single monomolecular layer of graphite with various oxygen containing functionalities such as epoxide, carbonyl, carboxyl and hydroxyl groups. Interaction of microcrystalline chitosan with graphene oxide. With abundant oxygenfunctionalities in its structure, go can potentially act as a suitable precursor for chemical modifications of graphene through methods used in organic. Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphenelike materials, is also discussed. Chemical graphitization from graphene oxide go to graphene has been introduced for mass production. A number of different models for graphene oxide have been proposed and tested using ab initio calculations. Among all studies on the chemistry of go, the largest portion focused on the reduction of go back to graphene, mainly due to its high relevance to graphene and the gold rush of graphene research over the last decade. Graphene is wellpoised to revolutionize many industries because of its multitude of exceptional properties. Oct 19, 2017 chemical reduction of graphene oxide by a mild and nonconventional reducing agent, fecl2hcl, produces optimally healed and ambient stable reduced graphene oxide with ultrahigh performance in supercapacitor applications, whereby the reducing agent can also be recycled. Synthetic routes contaminate graphene materials with a. Graphite oxide, formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers. This article supplies a facile route to prepare rgo sheets and we carefully investigates the structures and electrical properties of these rgo sheets.
Reduced graphene oxide and its natural counterpart. We show that the twocomponent model of graphene oxide go, that is, composed of highly oxidized carbonaceous debris complexed to oxygen functionalized graphene sheets, is a generic feature of the synthesis of go, independent of oxidant or protocol used. Recently, the synthetic protocol for graphite oxide was optimized and almost intact graphene oxide with a preserved carbon framework was obtained. Go has greater aqueous solubility than pristine graphene due to its oxygenfunctionalities. The use of the vapour phase is needed to pattern hydrophilic gos on prepatterned substrates, as well as in in situ reduction to hydrophobic reduced graphene oxides rgos.
Graphene oxide as a chemically tunable platform for optical applications. A theoretical study of graphene oxide chemical structure. Graphite oxide is an oxygencontaining and waterdispersible derivative of graphite, it can be exfoliated and well suspended in an aqueous medium even down to the singlelayer level form of graphene oxide go. Graphene has received so much attention due to its exceptional electronic, thermal, mechanical, and optical properties in addition to its large surface area and singleatom thickness.
The flow chart for synthesis of go is given in figure 3. Chemical reduction of graphene oxide using green reductants. Our strategy here is based on a reduction of go via eb irradiation under optimally controlled conditions, i. The chemical derivation of graphene oxide go provides a high yield of covalently functionalized, atomically thin carbon sheets 1,2. Sep 21, 2010 the mass production of highquality reduced graphene oxide could aid the scaleup of graphene based technologies. Cu 2 srgo composite developed for use as a counter electrode for quantum dot solar cells employing a sulfidepolysulfide redox couple graphene just might be the best thing since sliced, glutenfree, bread. The addition of chemical reducing agents to go solutions is common and many techniques. Nov 09, 2010 graphene nanosheets synthesis via chemical reduction of graphene oxide using sodium acetate trihydrate solution. Visible lightassisted photoreduction of graphene oxide. Graphenebased nanomaterials and their electrochemistry. Reduction, dispersity and electrical properties of graphene. The mass production of highquality reduced graphene oxide could aid the scaleup of graphenebased technologies.
Investigation of the reduction of graphene oxide by. See table 2 for a list of electrical properties of graph. Investigation of the reduction of graphene oxide by lithium. Defects within a sheet increase its chemical reactivity.
The singlelayer carbon allotrope is cheap, robust, has impressive surface area, and can be readily produced through chemical oxidation in the form of graphene oxide go. May 07, 2018 the chemical production of graphene as well as its controlled wet chemical modification is a challenge for synthetic chemists and the characterization of reaction products requires sophisticated analytic methods. Synthesis and fabrication of graphene and graphene oxide. This modified protocol thus eliminates the potentially. Graphene oxide vs graphene property go rgo graphene composition c 2 o c 5 o c 100 o c sheet thickness 1 nm 0. Here, a onepot reduction of graphene oxide using hydriodic acid and acetic acid. The chemical reduction of graphene oxide go is the most promising and effective method for the synthesis of reduced graphene oxide rgo because of its relatively large scale and low cost. Chemical reduction of graphene oxide to graphene by. Graphene nanosheets synthesis via chemical reduction of graphene oxide using sodium acetate trihydrate solution. Chemistry with graphene and graphene oxidechallenges for. In spite of the insulating properties of the thinfilmbased go due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film. Go recently emerged as a solutionprocessable material for. Reduction of this almost intact graphene oxide performs much better and the mobility values of charge carriers exceeds cm 2 vs for the best quality of flakes.
Chemistry with graphene and graphene oxide challenges. Among them, chemical reduction of go provides a facile route for largescale synthesis of graphene. Improved hole injection in bulk heterojunction bhj hybrid. This modified protocol thus eliminates the potentially hazardous second high. Among the large number of chemical reducing agents used to prepare rgo or graphene, the most efficient reductant is. Current bulk synthesis of graphene materials typically starts with the oxidation of graphite to graphite oxide followed by a reduction step. The onset temperature of reaction between the basal. We then outline the most important synthetic methods which are used for the production of these carbon. Reduced graphene oxide by chemical graphitization nature. Go powder thus obtained was dried at room temperature. Among the large number of chemical reducing agents used to prepare rgo or graphene, the most efficient reductant is hydrazine.
Thermal reduction of graphene oxide 300 600 0 20 40 60 80 100 221 260 temperature c s43 86 40%. Chun kiang chua and martin pumera, chemical reduction of graphene oxide. Graphene oxide vs graphene property go rgo graphene. Electrochemistry of graphene and related materials. Visible lightassisted photoreduction of graphene oxide using cds nanoparticles and gas sensing properties. The theoretical study of graphene oxide on the 24th australian conference on microscopy and microanalysis 2016. Chapter 3 synthesis of graphene oxide and reduced graphene oxide. Electromechanical behavior of chemically reduced graphene.
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