This nanotubenanosheet composite was deposited on electrode as active. The graphene oxide layers are revealed to play roles in providing geometric barriers for the mass transport channels of reactants rather than changing the chemical states of the znbased electrocatalysts according to in situ xray absorption spectroscopic analysis and electrochemical reaction kinetic studies. Jun 15, 2018 we demonstrate an electrochemical reduction method to reduce graphene oxide go to electrochemically reduced graphene oxide ergo with the assistance of carbon nanotubes cnts. Compared with hummers method, electrochemical exfoliation of graphite is considered facile and. Here we show that electrochemical reduction of go is highly sensitive to the cations present in the solution. Additionally, few reports have discussed what degree the graphite should be oxidized to bound for ef. Green reduction of graphene oxide by ascorbic acid. Electrochemical deposition of semiconductor oxides on. Effects of graphene oxide on microstructure and mechanical. Wei zhou, jinlong zheng, rong cheng, lin guo, xiang zheng. Reduced graphene oxides rgos have attracted considerable interest, given their potential applications in electronic and optoelectronic devices and circuits.
The produced films are mechanically robust, show high. The graphene oxide go was fabricated using modified hummers method and was electrochemically reduced on the surface of gce by performing cyclic voltammograms from 0 to. Preparation, characterization and their electrochemical properties article pdf available in chinese science bulletin 5723. Solidphase electrochemical reduction of graphene oxide films. Facile and controllable electrochemical reduction of graphene. Go plays important roles in the sustainable development of energy and the environment, taking advantages of oxygencontaining functional groups for good dispersibility and assembly. On the reduced graphene oxide rgo films, zno nanorods, as well as ptype and ntype cu2o films with good crystallinity have been electrochemically deposited and then characterized.
Functionalized graphene produced through reduction of graphene oxide displays a wrinkled structure due to the presence of lattice defects and this is different than the. The possibility of creating ultrathin membraneelectrode assemblies of supercapacitor cells was demonstrated. However, very little is known regarding the chemically induced reduction method of graphene oxide go in both solution. Some reported examples of graphene oxide reduction include. Coupled electronic and morphologic changes in graphene. In this paper, we reported a simple, efficient, and environmentally friendly electrochemical method to reduce go. In this paper, a hydrothermal method was used as a safe and green chemistry route for the reduction of graphene oxide. Erg is characterized with scanning electron microscopy, transmission electron microscopy, xray photoelectron spectroscopy, and xray diffraction. The reduced go adsorbed on glassy carbon electrode was modified with glucose oxidase gox by covalent bonding via a polymer generated by electrografting nsuccinimidyl acrylate nsa. Graphene has been produced by various methods and techniques from various precursors. We used a standard lightscribe dvd optical drive to do the direct laser reduction of graphite oxide films to graphene.
Go is reduced at lower potential in alkali metal chloride solutions than in. The peculiarities of the electrochemical behavior of films of different thicknesses that contact with carbon and metal current collectors were shown. Electrochemically reduced graphene oxide ergo film was characterized by xray diffraction, xray photoelectron spectroscopy, atomic force microscopy, and raman spectroscopy. Pdf solidphase electrochemical reduction of graphene. The methods which are capable of producing the highest quality graphene tend to be more complex. Electrochemical reduction of graphene oxide on zno. In the present work, graphene oxide gozno bilayer composites were fabricated by depositing go on zno by an anodic electrophoretic method. Jun 18, 2019 graphene and its derivatives such as graphene oxide go and reduced go rgo offer excellent electrical, mechanical and electrochemical properties.
Electrochemical reduction of graphene oxide films in. Change of the intensity ratio of two bands could be due to the increasing defects in reduced graphene oxide 14, 28 and shows that more new graphitic domains have been created and the number of sp 2 areas has increased. Electrochemical reduction of graphene oxide for industrial. This approach opens up a new, practical and green reducing method to prepare largescale graphene. We are breaking down graphite into graphne with a waterepson salt solution, electricity and some graphite.
The reduction of graphene oxide can be achieved a number of ways through thermal, chemical, or electrochemical methods. Flexible, transparent, and conductive electrodes are prepared by reduction of the graphene oxide go films which were spincoated on the polyethylene terephthalate pet substrates. Graphene oxide go film was evaporated onto graphite and used as an electrode to produce electrochemically reduced graphene oxide ergo films by electrochemical reduction in 6 m koh solution through voltammetric cycling. Jun 01, 2016 read analysis of electrochemical reduction process of graphene oxide and its electrochemical behavior, electroanalysis on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. In other words, the average size of sp 2 areas is reduced during the reduction of graphene oxide.
The process relied on the electrochemical reduction of go sheets deposited on the surface of cu electrode. Electrochemical reduction has been used to prepare graphene materials with onedimensional 1d to threedimensional 3d architecture. Electrochemically reduced graphene oxide sheets for use in. The graphene oxide was reduced electrochemically in phosphate buffer solution by applying potential of 0. Mass transport control by surface graphene oxide for. Although such electrochemical approaches can provide a more accurate control of the film thickness, they are poorly applicable to a largescale production 16. Reversible electrical reduction and oxidation of graphene. The main procedures involve the electrophoretic deposition of graphene oxide onto positive electrode and the subsequent in situ electrochemical negative reduction when the electrode changes from positive to negative. Highquality graphene via microwave reduction of solution. Page 1 of 38 accepted manuscript 1 electrochemical characterization of reduced graphene oxide coated polyester fabrics. Herein, reduced graphene oxide ergo with high porosity was driven by highvoltage ecd to form a binderfree capacitor electrode for lithium ion capacitors lics.
Facile and controllable electrochemical reduction of. When supporting electrolyte matters tuning capacitive. In this paper, the direct electrochemical reduction of zinc ions is studied using electrochemically reduced graphene oxide ergo modified glassy carbon electrode gce. The electrochemical method of reducing go may open up another way of controlling the reduction of go and the extent of reduction to obtain highly conducting graphene on electrode materials. Onestep electrochemical fabrication of reduced graphene. Graphite oxide with large lateral dimensions has an exfoliation yield of 100%, but it has not been possible to completely remove the oxygen functional groups so that the reduced form of graphene oxide go. Effects of graphene oxide on microstructure and mechanical properties of graphene oxide geopolymer composites. The electrochemical reduction of graphene oxide typically involves complicated procedures, such as modification of electrodes and preparation of electrolytes, which is often needed in previous reports.
Electrochemical reduction of the oriented graphene oxide film is carried out in a room temperature, ternary molten electrolyte. A simple and efficient electrochemical reductive method for. Several approaches have been developed for the synthesis of graphene, such as mechanical cleavage, epitaxial growth, chemical vapour deposition, electrochemical exfoliation of graphite,, and reduction of graphene oxide go that derived from chemical exfoliation of graphite. Pdf solidphase electrochemical reduction of graphene oxide. Solidphase electrochemical reduction of graphene oxide. Sep 20, 2018 this paper reports a facile and green method for conversion of graphene oxide go into graphene by lowtemperature heating 80 c in the presence of a glass wafer.
In particular, graphene for direct electrochemistry of enzyme, its electrocatalytic activity toward small biomolecules hydrogen peroxide, nadh, dopamine, etc. Here, we report a simple and novel method to prepare graphene oxide reduced graphene oxide gorgo nanocomposite hydrogelbased deformable actuators by local electrochemical reduction of homogeneous polynisopropylacrylamidego pnipamgo hydrogels. Graphene production via electrochemical reduction of. Author links open overlay panel shaw yong toh a kee shyuan loh a siti kartom kamarudin b wan ramli wan daud a. The ability to tune charge storage properties of graphene oxide g o is of utmost importance for energy conversion applications. The go and rgo films have been characterized by conductive afm that shows an increase in the current flow by at least 3 orders of magnitude after reduction. The faster and more efficient reduction of go can be achieved after proper addition of cnts into go during the reduction process. Electrochemical reduction of bulk graphene oxide materials. The high voltage was used to drive the continuous and constant reduction of graphene oxide as well as for generation hydrogen, which was responsible for the porous structure. Apr 17, 2009 simultaneous synthesis of diverse graphene via electrochemical reduction of graphene oxide. Magnetic field induced electrochemical performance. Unique copper and reduced graphene oxide nanocomposite toward. Journal of applied electrochemistry 2015, 45 5, 453462.
Thin film fabrication and simultaneous anodic reduction of. Graphene based electrochemical sensors and biosensors. A systematic study of the electrochemical reduction of graphene oxide was performed. According to the xray powder diffraction xrd, scanning electron microscopy sem, and electrochemical results, go were reduced with ascorbic acid like hydrazine with better electrochemical properties and ascorbic acid is an ideal substitute for hydrazine in the reduction of graphene oxide. Graphene oxide go is assembled on a gold substrate by a layerbylayer technique using a selfassembled cystamine monolayer. Journal of materials chemistry a 2014, 2 37, 15428. Pdf in situ reduction and functionalization of graphene. Thus, the graphene oxide has to be reduced to restore the unique properties found in the pristine graphene.
Pdf synthesis of graphene nano sheets by the rapid. One pot reduction and functionalization of graphene oxide go with lcysteine lcysrgo at the edges and basal planes of the carbon layers are presented. Analysis of electrochemical reduction process of graphene. A facile electrochemical preparation of reduced graphene. Electrochemical characterization of reduced graphene oxide. The negatively charged go platelets are attached to the positively charged cystamine monolayer through electrostatic interactions. Electrochemical impedance spectroscopy characterization of ergo. Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure. This nanotubenanosheet composite was deposited on electrode as active material for.
Here we propose a strategy of radical oxidation reaction for the highefficiency production of graphene oxide go. Graphene oxide films used in electrochemical reduction experiments were spin coated onto precleaned sno 2 substrates. Subsequently, it is shown that the go can be reduced electrochemically using applied dc bias by scanning the potential from 0 to 1 v vs a. We report the deposition of films composed of overlapped and stacked platelets of graphene oxide go reduced by an electrophoretic deposition epd process. A direct electrochemical method to reduce singlelayer graphene oxide go adsorbed on the 3aminopropyltriethoxysilane aptesmodified conductive electrodes is proposed.
The oxygen functional groups of go were significantly removed by the epd process, and the asdeposited go film by epd showed improved electrical conductivity 1. Graphene production via electrochemical reduction of graphene oxide. Graphene oxide go film was electrochemically reduced by a cyclic voltammetry technique in 6 mol l. Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene like materials, is also discussed. Fourier transformed infrared and raman spectroscopy confirmed the presence of ergo. The electron acts as the reducing agent directly during the electrochemical reduction, which gives efficient reduction with the conservation of the original structure of the graphene oxide go materials. The same electrode is first used as the anode for the electrophoretic deposition of go. To date, different reduction protocols have been employed for efficient reduction of graphene oxide go into rgo such as, thermal reduction. Laser scribing of highperformance and flexible graphene.
In this paper, graphite oxide was prepared from natural flake graphite by hummers method through liquid oxidization, and the reduced graphene oxide was obtained by chemical reduction of graphene oxide using nh 3 h 2 o aqueous solution and hydrazine hydrate. We demonstrate an electrochemical reduction method to reduce graphene oxide go to electrochemically reduced graphene oxide ergo with the assistance of carbon nanotubes cnts. Sep 07, 2018 electrochemical reduction of graphene oxide has been shown to create high quality rgo that is almost similar in terms of structure to pure graphene. Here we demonstrate a simple and fast method of electrochemical exfoliation of graphite to graphene oxide go and then its rapid reduction to graphene nanosheets gns with the help of microwaves. This process involves coating various substrates such as indium tin oxide or glass with a very thin layer of graphene oxide. Electrochemical reduction of graphene oxide youtube.
Electrochemical deposition of highly porous reduced graphene. Go is reduced at lower potential in alkali metal chloride solutions than in alkaline earth. In this paper, an electrochemical approach was described for preparing graphene with different microstructures, starting from aqueous solutions of graphene oxide go, processed under direct voltage. Unique copper and reduced graphene oxide nanocomposite toward the efficient electrochemical reduction of carbon dioxide skip to main content thank you for visiting. The composite films were then subjected to a cathodic electrochemical treatment with different go reduction times.
Study of reduced graphene oxide preparation by hummers. Graphene production via electrochemical reduction of graphene. A reduced graphene oxide based electrochemical biosensor. In this paper, we reported a simple, efficient, and environmentally friendly electrochemical method to. Photosynergetic electrochemical synthesis of graphene oxide. The graphene oxide and the electrochemically reduced graphene oxide were characterized using exsitu.
Pdf facile and controllable electrochemical reduction of. Despite the difference in the quality of the reduced graphene oxide from that of pristine graphene, the product from the reduction process could be further modified and used for a. Although electrochemical capacitors ecs, also known as supercapacitors or ultracapacitors, charge and discharge faster than batteries, they are still limited by low energy densities and slow rate capabilities. Graphene oxide is electrochemically reduced which is called electrochemically reduced graphene oxide erg. Further, due to the presence of high surface area, and a rich oxygen and defect framework, they are able to form nanocomposites with metalsemiconductor nanoparticles, metal oxides, quantum dots. Graphite, graphite oxide, graphene oxide, and reduced. The lcysrgo was characterized by xray diffraction studies xrd, xray photoelectron. Mar 27, 2015 in this paper, an electrochemical approach was described for preparing graphene with different microstructures, starting from aqueous solutions of graphene oxide go, processed under direct voltage. A simple and efficient electrochemical reductive method. Graphene and its derivatives such as graphene oxide go and reduced go rgo offer excellent electrical, mechanical and electrochemical properties. In the first one, go was obtained starting from an aqueous solution containing graphite in h2so4 and thereafter. An electrochemical synthesis of reduced graphene oxide. In this process, different substrates such as glass or indium tin oxide are coated with a thin layer of graphene oxide. Ruoff a, a department of mechanical engineering and the texas materials institute, the university of texas at austin, one university station c2200.
The electrochemically reduced graphene oxide ergo was characterized by uvvis, eis and zetapotential measurements. Graphene oxide go was reduced by a rapid, effective and ecofriendly electrochemical method of repetitive cathodic cyclic potential cycling, without using any reducing reagents. Electrochemical reduction of graphene oxide has been shown to create high quality rgo that is almost similar in terms of structure to pure graphene. Electrochemical reduction of graphene oxide is a method that has been shown to produce very high quality reduced graphene oxide, almost identical in terms of structure to pristine graphene, in fact.
Solidphase electrochemical reduction of graphene oxide films in alkaline solution. Direct electrochemical reduction of singlelayer graphene. Analysis of electrochemical reduction process of graphene oxide and its electrochemical behavior mingming gao shandong provincial key laboratory of water pollution control and resource reuse, school of environmental science and engineering, shandong university, jinan, 250100, china. The graphene oxide and the electrochemically reduced graphene oxide were characterized using exsitu field. Reduced graphene oxidecarbon nanotube composites as. Further, due to the presence of high surface area, and a rich oxygen and defect framework, they are able. It is graphene oxide that is the product obtained by hummers method, and hence it is graphene oxide that undergoes the reduction to graphene, or more precisely go is reduced to rgo. It is observed that optical and electronic property changes are correlated withtheformationofagraphene. This hybrid material has been used to fabricate the electrodes of an electrochemical double layer supercapacitor. Biosensors free fulltext influence of graphene oxide. In this paper, a simple and efficient electrochemical process is described for the synthesis of highquality reduced graphene oxide. A reduced graphene oxide based electrochemical biosensor for. Pdf electrochemical reduction of graphene oxide films.
Another reported method to design graphene based spes is the direct electrochemical reduction of the dispersed graphene oxide at the substrate electrode 54,55. The raw material graphite, graphite oxide, and reduced graphene oxide were. In this way, the present work explores two ways to obtain ergo using a combination of hummers3 and potentiostatic methods. Electrochemical reduction of oriented graphene oxide films. Synthesis of graphene oxide nanosheets by electrochemical exfoliation of graphite in cetyltrimethylammonium bromide and its application for oxygen reduction. The types of cells and methods of electrochemical reduction of graphene oxide films were described. A convenient method for the production of graphene is developed using the electrochemical reduction of graphite oxide go in solution without assembling it onto the electrode. Thermoresponsive deformable actuators prepared by local. Unique copper and reduced graphene oxide nanocomposite. Clearly, rgoi exhibits a similar structural morphology to rgoii and rgoiii shown in fig s1 e and f, indicating that the further reduction process does not affect the 3d porous structure of rgo. The electrochemical reduction of go was investigated in aqueous media as shown in fig. Facile reduction of graphene oxide suspensions and films. Erg exhibits much higher electrochemical capacitance and cycling durability than carbon nanotubes cnts and chemically reduced graphene. Potts a, aruna velamakanni a, shanthi murali a, rodney s.
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