Thermally reduced graphene oxidecarbon nanotube composite. Reduce graphene oxide has suitable functional groups such as carboxyl, epoxyl and hydroxyl, go produced by vigorous oxidation of graphite by hummers method, is an ideal nanocarrier for efficient drug and gene delivery. Among various methods used for the reduction of graphene oxide go into a purer form of graphene, the thermal reduction method provides a simpler, safer, and economic alternative, compared to other techniques. Reduced graphene oxide rgo can be extracted as thin film from an aqueous solution of graphite oxide go slurry. We demonstrate reduced graphene oxide as the active material for highperformance molecular sensors. Rutile structure is confirmed for sno 2 and rgosno 2. Paper open access related content synthesis of reduced. The detailed experimental procedure is given in additional file 1.
Application fields graphene and polymers manufacture, water purification, flexible rechargeable battery electrode, optically. The advantage rgo has over graphene is that it can be stored longer without agglomeration. This graphene material is called reduced graphene oxide, often abbreviated to rgo. Reducing graphene oxide to graphene using environmentally.
Facile assembly of 3d porous reduced graphene oxide. Reduced graphene oxide thin film on conductive substrates by. These graphene oxide networks are tunably reduced toward graphene by varying the exposure time to a hydrazine hydrate vapor. A correction has been published and is appended to both the html and pdf versions of this paper. Synthesis and characterization of graphene oxide and. Keywords graphene oxide, transmission electron microscopy, defects s ince the discovery of graphene,1 a twodimensional atomic sheet entirely made of carbon, immense efforts have been directed toward the development of reliable methods for obtaining large quantities of this extraordinary material. Page 4 typical tem image 3 of acs material reduced graphene oxide rgo 3. Electrical and thermal conductivities of reduced graphene oxidepolystyrene composites wonjun park,1,2,a jiuning hu,1,2 luis a. However, very little is known regarding the chemically induced reduction method of graphene oxide go in both solution. Many modern procedures for the synthesis of go are based on the hummers method, in which graphite is oxidized by.
Indocyanine greenloaded polydopaminereduced graphene oxide. Thereafter, graphene oxide go was pre pared by the exfoliation of the graphite oxide in distilled water in an ultrasonicator. Optical properties of reduced graphene oxide insights from ab initio and hybrid density functional theory mark james lundie school of computing, science and engineering university of salford, salford, uk submitted in partial ful. The rgo aerogels were used to remove pbii from aqueous. By a simple solvothermal reaction process, nanosized s atoms are homogeneously decorated into the 3d scaffold formed by reduced graphene oxide rgo and mno 2 nanosheets, which can form the homogeneous rgm. Table 1 compiles the main characteristics of the nondoped and ndoped reduced graphite oxides obtained. Reducing graphene oxide to produce reduced graphene oxide hitherto referred to as rgo, is an extremely vital process as it has a large impact on the quality of the rgo produced, and therefore will determine how close rgo will come, in terms of structure, to pristine graphene. The maximally oxidized bulk product is a yellow solid with c. This process is carried out thermally, chemically, or through ir or uv irradiation to obtain a powder form.
Safe and reliable znbased batteries with high volumetric energy density are critical for wearable and compact electronic devices. These are some examples of our recent publications. Research across multiple disciplines has put it alone at the topmost concern due to unique physiochemical properties. Herein, we report a facile solutionprocessable approach to create inplane nanopores on go nanosheets before reduction, dramatically decreasing the. Synthesis of graphene oxide go by modified hummers. Efficient reduction of graphene oxide to obtain highquality graphene nanosheets is desirable for energy storage, catalysis, electronics and environmental remediation. Reduced graphene oxide and its natural counterpart. Sensors are fabricated from exfoliated graphene oxide platelets that are deposited to form an ultrathin continuous network. Superior catalytic activity and stability are obtained in the aerobic oxidative desulfurization process catalyzed by rgo. The bulk material spontaneously disperses in basic solutions or can be dispersed by sonication in polar solvents to yield monomolecular sheets, known as graphene oxide by analogy to graphene, the singlelayer form of graphite. Using suitable choice of reaction parameters including temperature and time, this recipe does not. The main ingredient for the synthesis of reduced graphene oxide is graphene oxide. Reduced holey graphene oxide membranes for desalination.
Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene like materials, is also discussed. Pdf toxicity and transformation of graphene oxide and. Synthesis of multifunctional cufe 2 o 4 reduced graphene oxide nanocomposite. Starting from the same graphene oxide, chemical crgo, hydrothermal. Herein, reduced graphene oxide rgo could be used as catalysts in oxidative desulfurization reactions for the first time to remove sulfurcontaining compounds from fuels. The resulting colloidal films are flexible and have uniform morphologies with improved structural colors. As much concentration we take initially, that much amount rgo we get at the end of the process.
It can be produced by micromechanical exfoliation of highly ordered pyrolytic graphite, epitaxial growth, chemical vapor deposition, and the reduction of graphene oxide go. It not only serves as a precursor for making reduced graphene oxide. Vernadskii institute of general and inorganic chemistry of the ukrainian nas, prospekt palladina 3234, 03680, kyiv 142, ukraine a method for the chemical synthesis of reduced. Despite their excellent gravimetric performance, the actual volumetric energy density of developed znbased batteries remains far from satisfactory, mainly owing to insufficient 2019 journal of materials chemistry a hot papers. An ultradense nis2reduced graphene oxide composite. Healing reduced graphene oxide films by supersonic. Electronic and optical properties of reduced graphene oxide. Highly ordered and dense thermally conductive graphitic. Graphene is regarded as the ultimate material for future flexible, high. Research into effective yet inexpensive ways to make derivatives or related materials has attracted tremendous interest. Probing the mechanical properties of verticallystacked ultrathin graphene al2o3 heterostructures nanotechnology19 february 2019 electrochemically active ir nps on graphene for oer. In this study, reduced graphene oxide rgo aerogels were successfully prepared using a facile hydrothermal method and determined with fourier transform infrared spectroscopy, xray diffraction spectroscopy, raman spectroscopy, xray photoelectron spectroscopy, brunaueremmettteller surface area, and scanning electron microscopy.
The structure of graphene oxide is similar to graphene containing residual oxygen, heteroatoms and structural defects. In this study, we investigated the directional heating of graphene oxide go dispersion to generate a temperature gradient and form a simulated ocean current inside the dispersion so that go sheets could be aligned in a directional manner and then reduced and selfassembled into anisotropic reduced graphene oxide rgo gel. While graphite is a 3 dimensional carbon based material made up of millions of layers of graphene, graphite oxide is a little different. Superparamagnetic reduced graphene oxide with large magnetoresistance.
Subsequently reduced graphene oxide rgo having few layer graphene is extracted from go by the thermal reduction of go. The further studies revealed the substantial structure imperfection of graphene oxide. Results of the reduced graphene oxide measurements. Oct 25, 2016 the advantage rgo has over graphene is that it can be stored longer without agglomeration. Reduced graphene oxide 250mg, 500mg size sigmaaldrich. Graphite, graphite oxide, graphene oxide, and reduced. Available formats pdf please select a format to send. Go was later reduced thermally to obtain reduced graphene oxide rgo. Superparamagnetic reduced graphene oxide with large. The oxidativeexfoliation methods can potentially produce large quantities of graphene oxide go, a graphene like nanosheet which is typically defective and requires additional treatments to. To obtain go sheets, graphite oxide was dispersed into distilled water 0.
Here, raphene oxide g go was prepared by oxidizing the purified natural flake graphite nfgby a mo dified hummers method. Here, we report a solutionbased method that allows uniform and controllable deposition of reduced graphene oxide thin. A surface modulation strategy jing peng hefei national laboratory for physical sciences at the microscale, ichem collaborative innovation center of chemistry for energy materials, hefei science center cas and cas key laboratory of mechanical behavior and design of. Electrical and thermal conductivities of reduced graphene. Graphene oxide go is useful and promising material for graphene based applications in electronic, optics, chemistry, energy storage, and biology. In situ doping of halide in a graphene film has many problems. Preparation of reduced graphene oxide aerogel and its. Graphite oxide has a similar layered structure to graphite, but the plane of carbon atoms.
The unique structural features, such as large and planar sp2 hybridized carbon domain. Advances in microwaveassisted production of reduced graphene. Tunable electrical conductivity of individual graphene oxide. Similar efforts are now being devoted to making the integration of graphene into devices technologically feasible710. Water dispersible magnetitereduced graphene oxide composites. Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure. Therefore, rgo is mentioned as graphene in many works.
Reduced graphene oxidesulfopropyl methacrylate potassium salt rgospm substrate may greatly decrease the transverse tensile stress across the colloidal film. Potts a, aruna velamakanni a, shanthi murali a, rodney s. We report a new approach to making highly dense, oriented, and crystalline graphite films from heattreated and pressed graphene oxide go. What is the difference between reduced graphene oxide and. Graphene oxide sheets have been used to prepare strong paperlike materials, membranes, thin films, and composite. Apr 28, 2016 here, we report a novel phototheranostic nanoagent using indocyanine greenloaded polydopamine reduced graphene oxide nanocomposites icgpdargo with amplifying pa and ptt effects for cancer theranostics. Reduced graphene oxide modified activated carbon for improving power generation of aircathode microbial fuel cells volume 33 issue 9 yang yang, tianyu liu, hanyu wang, xun zhu, dingding ye, qiang liao, ke liu, shaowei chen, yat li. The effectiveness of this oxidation process can be evaluated by the magnitude of carbonoxygen ratio of the obtained graphene. Mar 26, 2020 graphene oxide go is a graphene based material that has gained significant interest in the last two decades 1,2 due to its straightforward, scalable, and lowcost synthesis. Graphene oxide is a form of graphene that includes oxygen functional groups, and has interesting properties that can be different than those of graphene. By the oxidation of graphite using strong oxidizing agents, oxygenated functionalities are introduced in the graphite structure which not only expand the layer. Applications of graphene oxide and reduced graphene oxide. Synthesis of reduced graphene oxidetio 2 composite. Synthesis and characterization of reduced graphene oxide.
Graphene oxide go is a graphene based material that has gained significant interest in the last two decades 1,2 due to its straightforward, scalable. The process started with the chemical oxidation of commercial graphite powder into graphite oxide by modified hummers method, followed by the exfoliation of graphite oxide in distilled water using the ultrasound frequency from a laboratory ultrasonic bath. In this porous network architecture, rgo serves as an electron and ion transfer pathway, a physical adsorption site for. Synthesis of multifunctional cufe2o4reduced graphene oxide. Special issue synthesis and applications of graphite oxide.
Synthesis, properties, and applications of graphene oxidereduced. Initially graphite oxide was prepared by oxidizing the purified natural flake graphite nfg by the modified hummers method. But much higher amount of graphene oxide can leads to incomplete reduction and thus bad quality final product. Reduced graphene oxidetio 2 nanocomposite as a promising. The preparation of reduced graphene oxide and its photothermal therapy of gliomas in vivo and in vitro haisheng wang1, hongxia chen2, yuehong ma3 1college of basic medical sciences, inner mongolia medical university, jinshan development zone, hohhot, inner.
A new approach to synthesize graphene is oxidizing graphite powder with a mixture of h 2 so 4 h 3 po 4 acids and potassium permanganate. Parameters such as reaction time, reaction temperature, and amount of concentration were varied to study the degree of oxidation of graphite to graphene oxide. A lowcost nonexplosive synthesis of graphene oxide for. Currently, an improved method for the preparation of graphene oxide was the most common one. Graphene oxide go can be regarded as one typical twodimension structured oxygenated planar molecular material. Studies on tio2reduced graphene oxide composites as cathode. Atmospheric plasma has been reported to reduce graphene oxide and, since electric discharge consists of atmospheric plasma it can be safely assumed that the plasma produced in the process of electric discharge also contributes to reduction of graphene oxide. Following thermal exfoliation and reduction, the 001 band completely disappears. The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. In this study, three types of graphene filmshydrothermal reduced graphene oxide go film, thermal reduced go film, and go filmon silicon substrate by using 3aminopropyl triethoxysilane aptes as the interface adhesive layer were prepared for investigation. So in the reduced graphene oxide there is always some defects and even though we try to reduce the graphene oxide, there are still some oxygen functional groups in or on the reduced graphene oxide.
Graphite oxide has a similar layered structure to graphite. The structural parameters of the rgos are shown in table 6. The reduced go rgo sheets are usually considered as one kind of. Compared to ordinary graphite, and graphite oxide, rgo have superior capacitive behavior and power output in edlcs due to their unique nanoporous structure. Ruoff a, a department of mechanical engineering and the texas materials institute, the university of texas at austin, one university station c2200. Reduced graphene oxides rgos have attracted considerable interest, given their potential applications in electronic and optoelectronic devices and circuits. However, their water permeances are much lower because of the high tortuosity for water permeation. Fast and fullyscalable synthesis of reduced graphene oxide.
In this study, we compared the impact of graphene oxide go and reduced graphene oxide rgo on biofilm formation and development in luriabertani lb. Structure and chemistry of graphene oxide in liquid water. Xrd patterns of graphite, graphite oxide, reduced graph openi. Reduced graphene oxide thin film on conductive substrates by bipolar electrochemistry.
Thermally reduced graphene oxide carbon nanotube composite films for thermal packaging applications guangjie yuan 1, jiefei xie 2, haohao li 2, bo shan 2, xiaoxin zhang 2, johan liu 2,3, long li 1 and yingzhong tian 1, 1 shanghai key laboratory of intelligent manufacturing and robotics, school of automation and mechanical. Reduced graphene oxide powders can be purchased from ossila either as a chemically reduced powder or thermally reduced powder. After chemical reduction by hydrazine, the sharp 002 peak of graphite oxide disappeared while another broad peak of around 24 shows up. As mentioned above, go is reduced to obtain rgo figure 1. By introducing smalldiameter reduced graphene oxide rgo flakes into the graphene oxide starting material, we found that after heat treatment at 3,000c, the sample density and atomic order substantially improved over a film composed, at the outset. The disadvantage is that it is not pristine without defects the advantage of rgo over graphene oxide is that it is c. We supply reduced graphene oxide rgo in powder form, dispersed, or as a coating on substrates. The modification of duallayer with 1pyrenebutyric acid nhydroxysuccinimide ester pyrnhs is achieved to facilitate immobilization of h31l21 antibody. Hydrazinereduction of graphite and graphene oxide sungjin park a,b, jinho an a, jeffrey r.
Electric spark induced instantaneous and selective. Just accepted is an optional service offered to authors. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide r. Reduced graphene oxide rgo membranes with narrow channels exhibit salt rejections comparable to conventional nanofiltration nf membranes. Application fields graphene and polymers manufacture, water purification, flexible rechargeable battery electrode, optically transparent films, papers, sensors, nanocarriers for metal catalysis, anti. Sigmaaldrich offers a number of graphene oxide products. Reviewnonenzymatic hydrogen peroxide electrochemical. By reducing graphene oxide, these oxidized functional groups are removed, to obtain a graphene material. Reduced graphene oxide go is prepared from graphite electrode using electrochemical exfoliation.
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. Original article the preparation of reduced graphene oxide. A labelfree biosensor based on graphene and reduced. The disadvantage is that it is not pristine without defects the advantage of rgo over grapheneoxide is that it is c. Partial reduction of graphene oxide to rgo is confirmed by infrared and raman spectroscopic techniques. The process involved preparation of graphene oxide and its chemical reduction with different reductants to obtain reduced graphene oxide. Jan 28, 2019 graphene oxide go is useful and promising material for graphene based applications in electronic, optics, chemistry, energy storage, and biology. The 002 peak of graphene oxide go is shifted to 14. At the beginning of graphene history go was only a simple and cheap step for preparation of single and multilayer graphene films and bulk structures by reduction. Preparation and characterization of reduced graphene oxide. Graphene oxide consists of highly oxidized carbon atoms, made by chemical oxidation of graphite. Pdf this paper describes a novel approach to the preparation of reduced graphene oxide and its dispersions in organic solvents.
Characterization of graphite oxide and reduced graphene. Nanotribology studies of reduced graphene oxide films in air. Controlled reduction of graphene oxide is an alternative and promising method to tune the electronic and optically active energy gap of this twodimensional. In this technique, different halides individually or all of them were mixed with the rgo and ionic liquids precursor at h2so4 solution. Synthesis of graphene oxide go by modified hummers method. Reduced graphene oxide membrane induced robust structural. Dec 14, 2015 in this research, the reducibility of three green reductants, lascorbic acid, dglucose and tea polyphenol, for graphene oxide was comparatively investigated.
All reduced graphene oxides were examined by the same methods as those employed for the graphite oxides, and xrd measurements were performed first. Fabrication and characteristics of reduced graphene oxide. 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. Graphene has attracted great interest for its excellent mechanical, electrical, thermal and optical properties. Impact of graphene based material gnms on bacteria biofilm has not been well understood yet. Graphene oxide go has been initially prepared by a modified hummersmethod. Reviewnonenzymatic hydrogen peroxide electrochemical sensors based on reduced graphene oxide hamed shamkhalichenar1, and jinwoo choi1,2,z 1school of electrical engineering and computer science, louisiana state university, baton rouge, louisiana 70803, united states of america 2center for advanced microstructures and devices, louisiana state university, baton rouge, louisiana 70803, united. This research studied the synthesis of graphene oxide and graphene via a lowcost manufacturing method. Reduced graphene oxide is a form of graphene oxide that has had oxygencontaining groups removed in order to make the flakes more similar in terms of properties to pure graphene. Synthesis of reduced graphene oxide rgo from graphene. Bactericidal effect of graphene oxide and reduced graphene oxide. Chen4,2,1,b 1school of electrical and computer engineering, purdue university, west lafayette, indiana 47907, usa 2birck nanotechnology center, purdue university, west lafayette, indiana 47907, usa. The lascorbic acid solution was mix together with gos and gows.
For example, it is known that the carbon to oxygen atomic ratio and electrical conductivity of reduced graphene oxide varies depending on chemical identity of the. A low cost, nonexplosive process for the synthesis of graphene oxide go is demonstrated. The first three methods can produce graphene with a. Tunable electrical conductivity of individual graphene oxide sheets reduced at low temperatures inhwa jung, dmitriy a. Graphite oxide was prepared from graphite powder by modified hummers method 2325. Thanks to its excellent electrical conductivity, the product is used in a number of research projects. Pdf graphene has attracted great interest for its excellent mechanical, electrical, thermal and optical properties. However, knowledge about the structure of go is still in argument and ongoing to update.
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