Reduction, dispersity and electrical properties of. Chemistry with graphene and graphene oxidechallenges for. Chun kiang chua and martin pumera, chemical reduction of graphene oxide. Chapter 3 synthesis of graphene oxide and reduced graphene oxide. Chemical synthesis and applications of graphene and carbon. Synthesis of graphene oxide and reduced graphene oxide page 70 to exfoliate the layers figure 3. 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, characterization, chemical reduction and. The theoretical study of graphene oxide on the 24th australian conference on microscopy and microanalysis 2016. 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. Graphene has the highest ratio of edge atoms of any allotrope. Among the large number of chemical reducing agents used to prepare rgo or graphene, the most efficient reductant is.
Chemical reduction of graphene oxide using green reductants. Synthetic routes contaminate graphene materials with a. This modified protocol thus eliminates the potentially hazardous second high. Improved hole injection in bulk heterojunction bhj. 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. The maximally oxidized bulk product is a yellow solid with c. With abundant oxygenfunctionalities in its structure, go can potentially act as a suitable precursor for chemical modifications of graphene through methods used in organic. The reduced graphene oxide suspension in the mixture of. 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 main simulation and computation theories to establish these structure. The debris present, roughly onethird by mass, can be removed by a base wash. Production of graphene oxide from pitchbased carbon fiber.
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. 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. Thanks to its specific chemical and physical properties, graphene has aroused growing interest in many fields of science and technology. Thermal reduction of graphene oxide 300 600 0 20 40 60 80 100 221 260 temperature c s43 86 40%. Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphenelike materials, is also discussed. Chemistry with graphene and graphene oxide challenges for. Interaction of microcrystalline chitosan with graphene. Modifying graphite oxide nanostructures in various media by highenergy irradiation lei chen et. Go has greater aqueous solubility than pristine graphene due to its oxygenfunctionalities. Many different methods exist for both the oxidation and reduction steps, leading to highly variable types and amounts of metallic contaminations. Visible lightassisted photoreduction of graphene oxide using cds nanoparticles and gas sensing properties. Chemical graphitization from graphene oxide go to graphene has been introduced for mass production.
Large scale production of graphene can also be effectively realized through chemical reduction of graphene oxide. Among them, chemical reduction of go provides a facile route for largescale synthesis of graphene. Electrochemistry of graphene and related materials. This work is presenting a highly efficient, costefficient and environmentally friendly method for the production of graphene materials reduced graphene oxide, redgo via electron beam eb irradiation of aqueous dispersions of graphene oxide go. Selective removal of hydroxyl groups from graphene oxide. Structural evolution during the reduction of chemically. A theoretical study of graphene oxide chemical structure. Sep 21, 2010 the mass production of highquality reduced graphene oxide could aid the scaleup of graphene based technologies. The chemical derivation of graphene oxide go provides a high yield of covalently functionalized, atomically thin carbon sheets 1,2. 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. Reduced graphene oxide rgo has been extensively investigated in past reports. Graphene is a 2d carbon material made up entirely of conjugated sp 2 carbons arranged in a honeycomb structure. A simple and efficient method to prepare graphene by. 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.
Here, a onepot reduction of graphene oxide using hydriodic acid and acetic acid. Reduction, dispersity and electrical properties of graphene. Go powder thus obtained was dried at room temperature. Chemistry with graphene and graphene oxide challenges. Go recently emerged as a solutionprocessable material for. Graphene nanosheets synthesis via chemical reduction of graphene oxide using sodium acetate trihydrate solution. 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. Concomitant thionation and reduction of graphene oxide through solidgas metathetical sulfidation reactions at high temperatures. A number of techniques, including solid state nmr, demonstrate. Graphene oxide and reduced graphene oxide, product developments for upcoming applications.
Graphene oxide vs graphene property go rgo graphene composition c 2 o c 5 o c 100 o c sheet thickness 1 nm 0. This modified protocol thus eliminates the potentially. In this work, the utilization of graphene oxide go, reduced graphene oxide rgo, and carbon nanotube cnt thin films as hole transport and electronblocking layers in polymernanocrystal hybrid solar cells is demonstrated. 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.
Graphite oxide was prepared from natural graphite by the well known. Various solutionbased chemical methods can be applied to go, which has stimulated a new research area called wet chemistry of grahene. Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene like materials, is also discussed. 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. 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. Visible lightassisted photoreduction of graphene oxide. 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. Graphene oxide vs graphene property go rgo graphene. Since graphene was first reported in 2004, made using. We then outline the most important synthetic methods which are used for the production of these carbon. Reduced graphene oxide by chemical graphitization nature. Synthesis and fabrication of graphene and graphene oxide. Currently, a number of techniques are used to produce graphene and these include epitaxial growth, chemical vapour deposition cvd, and thermal or mechanical exfoliation. The onset temperature of reaction between the basal.
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. Defects within a sheet increase its chemical reactivity. 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. Investigation of the reduction of graphene oxide by. Graphene is wellpoised to revolutionize many industries because of its multitude of exceptional properties. Graphene oxide, reduced graphene oxide, graphene, carbocatalyst, oxidation, reduction. To this extent, it deals with topdown and bottomup approaches across the different length scales for graphene from polycyclic aromatic hydrocarbons to graphene nanoribbons and. The mass production of highquality reduced graphene oxide could aid the scaleup of graphenebased technologies. See table 2 for a list of electrical properties of graph. Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure. Highlevel supercapacitive performance of chemically reduced. 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.
Improved hole injection in bulk heterojunction bhj hybrid. The chemical reduction of a wet colloidal suspension of graphene oxide is a costeffective and adaptable method for large scale production of quasi graphene for a wide variety of optoelectronic applications. The artemisinin was used for the reduction of graphene oxide. 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. The chemical reduction of graphene oxide is a promising route towards the large scale production of graphene for commercial applications. The preparation of reduced graphene oxide rgo by chemical reduction of.
Our strategy here is based on a reduction of go via eb irradiation under optimally controlled conditions, i. Graphenebased nanomaterials and their electrochemistry. Among the large number of chemical reducing agents used to prepare rgo or graphene, the most efficient reductant is hydrazine. The flow chart for synthesis of go is given in figure 3. Investigation of the reduction of graphene oxide by lithium. The reduced approaches are greatly important for rgo sheets applied in electrical, optical and electrochemical fields.
Recently, the synthetic protocol for graphite oxide was optimized and almost intact graphene oxide with a preserved carbon framework was obtained. Graphene oxide go, the functionalized graphene with oxygenated groups mainly epoxy and hydroxyl, has attracted resurgent interests in the past decade owing to its large surface area, superior physical and chemical properties, and easy composition. Chemical reduction of graphene oxide to graphene by sulfur. Graphene chemistry drastically differs from the conventional molecular one and presents a. Nov 09, 2010 graphene nanosheets synthesis via chemical reduction of graphene oxide using sodium acetate trihydrate solution. Chemical reduction of graphene oxide to graphene by. 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. Physical properties and device applications of graphene oxide.
Applications of graphene oxide and reduced graphene oxide. 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. In this chapter, we discuss a variety of chemical reactions introduced for go. Graphene oxide as a chemically tunable platform for optical applications. Graphene based nanomaterials and their electrochemistry. Graphene was prepared by a simple chemical reduction of graphite oxide in the dimethylacetamide dmach 2 o mixture solvent. Interaction of microcrystalline chitosan with graphene oxide.
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. Synthesis, properties, and applications of graphene oxidereduced. Current bulk synthesis of graphene materials typically starts with the oxidation of graphite to graphite oxide followed by a reduction step. Reduced graphene oxide and its natural counterpart. 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. This article supplies a facile route to prepare rgo sheets and we carefully investigates the structures and electrical properties of these rgo sheets. Facile synthesis of graphene via reduction of graphene oxide by. 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. 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. Electromechanical behavior of chemically reduced graphene. A simple method has been used to modify the anode of hybrid solar cells by depositing these two solutionprocessable nanocarbon materials between poly3,4. 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.
Atoms at the edges of a graphene sheet have special chemical reactivity. This study introduces a new structural model of graphene oxide and its theoretical electronic properties. 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. The addition of chemical reducing agents to go solutions is common and many techniques. A simplified chemical reduction method for preparation of.