Harish Mudila; Sweta Rana; Mohammad G. H. Zaidi
Abstract
A series of Polyindole/Graphene nanocomposites (PGNCs) as electrochemical energy storage materials were fabricated at varying concentration (%, w/w) of graphene raging 3.0–9.0 in Polyindole (PIN) matrix in Supercritical CO2. The electrochemical behavior of PGNC prepared at different proportion ...
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A series of Polyindole/Graphene nanocomposites (PGNCs) as electrochemical energy storage materials were fabricated at varying concentration (%, w/w) of graphene raging 3.0–9.0 in Polyindole (PIN) matrix in Supercritical CO2. The electrochemical behavior of PGNC prepared at different proportion of graphene was investigated. The PGNC@9% has rendered specific capacitance of 389.17 F/g, along with energy and power densities of 13.51 Wh/kg and 511.95 W/kg respectively, which is greater as compared to graphene prepared through thermal reduction of graphene oxide. However, PIN comprises low capacitance of 24.48 F/g. Successive scans of PGNCs electrode for 1000 cycles at the scan rate of 0.1 V/s in KOH (1.0 M) shows a capacitive retention of ~98.6% indicating the electrochemical stability of the electrodes, with successive charge-discharge behavior. PGNCs display all the major peaks in Fourier Transform-Infrared and X-Ray diffraction spectra. Scanning electron micrograph in permutation with XRD spectra indicates the exfoliation of graphene into the matrix of PIN. Simultaneous TG-DSC reveals increased thermal stability of PGNCs with fractions of graphene. The good capacitive and charge-discharge performance indicates that supercritically fabricated PGNCs may serve as potential electrode materials for electrochemical energy storage devices.
Issam Derkaoui; Mohammed Khenfouch; Ibrahim Elmokri; Bakang M. Mothudi; Mokhotjwa S. Dhlamini; Sabata J. Moloi. Anouar Jorio; Izeddine Zorkani; Malik Maaza
Abstract
Most recently, Vanadium oxide nanoparticles/reduced Graphene oxide (VO-NPs/rGO) nanocomposite have attracted extensive attention due to their potential applications in energy-related areas. Hence, understanding the interactions on behalf the effect of graphene layers on the modification of VO-NPs properties ...
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Most recently, Vanadium oxide nanoparticles/reduced Graphene oxide (VO-NPs/rGO) nanocomposite have attracted extensive attention due to their potential applications in energy-related areas. Hence, understanding the interactions on behalf the effect of graphene layers on the modification of VO-NPs properties as well as their growth mechanism are of great importance. In this work, our results are revealing that VO-NPs were efficiently grown and coated on the graphene surface and are clearly showing the strong effect of rGO layers on the growth of VO-NPs which leads to a modification in the form, the shape and also the phase. These interactions which were studied based on structural and morphological investigations will play an important role on the modification of these nanocomposites properties which is suitable for a wide range of potential applications and particularly as electrode in Li-ion batteries.
L. S. Lima
Abstract
We have employed the Dirac's massless quasi-particles together with the Kubo's formalism of the linear response to study the spin transport properties by electrons in the graphene monolayer. We have calculated the electric conductivity and verified the behavior of the AC and DC currents of this ...
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We have employed the Dirac's massless quasi-particles together with the Kubo's formalism of the linear response to study the spin transport properties by electrons in the graphene monolayer. We have calculated the electric conductivity and verified the behavior of the AC and DC currents of this system, which is a relativistic electron plasma. Our results show a superconductor behavior for the electron transport with the AC conductivity tending to infinity in the limit ω → 0. This superconductor behavior for the electron transport in the graphene is similar to one recently obtained theoretically for the spin transport in the quantum frustrated Heisenberg antiferromagnet in the honeycomb lattice, verifying so a similarity between these two different kinds of transport what can generate futures applications in the modern electronic.
M. Sivaprasad; N. Y. Sreedhar; M. R. Jayapal; Li Yang; Hongwei Ni
Abstract
Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) ...
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Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) and used as an electrochemical sensor for determination of Tetrachlorvinphos (TCP < /span>) pesticide in vegetables. Here most of the work has been focused on the preparation and characterization of modified electrode with cyclic voltammetry (CV) and scanning electron microscopy (SEM). The modified composite electrode unveiled significantly good voltammetric response on TCP. Square wave voltammetry (SWV) was used for determination of TCP at optimized conditions such as square wave frequency, step potential, pH of buffer, applied sample volume, accumulation potential and accumulation time. The well-defined reduction (C=C) peaks were acquired over the potential maximum around at -1.3V in acidic medium in Briton-Robinson (B-R) buffer solution at low current values. The low current peaks were obtained over the concentration of TCP at 1.5×10 -6 M with lower detection limit and limit of quantifications are 5.62×10 -10 M and 2.65×10 -8 respectively. The composite modified electrode showed good stability and reproducibility. The proposed method was successfully applied for the present investigation with a great assure as an economical and simple sensor with furthermore a shorter analysis time and further the sensor also used for heavy metal detection in real samples.
Ashutosh Tiwari
Abstract
The design of innovative materials is one of measure for driving industry to place the sustainable basis of new technology in order to enhance the wealth and well-being of society. The last half century has realized a vital development in the area of high-tech materials ranging from various elements ...
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The design of innovative materials is one of measure for driving industry to place the sustainable basis of new technology in order to enhance the wealth and well-being of society. The last half century has realized a vital development in the area of high-tech materials ranging from various elements and composites, emerged through synthetic chemistry and often drawing motivation from the nature. The idea of an intelligent material imagines added values in terms of functionality built into the materials structure desirable to response the defined conditions. The previous two decades has emerged to understand the extraordinary behavior and properties of engineered nanostructured materials.
Ashutosh Tiwari
Abstract
VBRI Press is pleased to announce ‘Global Graphene Forum, during 23 – 25 August 2016, Sweden. It is a three-day international event organised with collaboration of International Association of Advanced Materials (IAAM), and Linkoping University on the Baltic Sea from Stockholm-Helsinki-Stockholm ...
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VBRI Press is pleased to announce ‘Global Graphene Forum, during 23 – 25 August 2016, Sweden. It is a three-day international event organised with collaboration of International Association of Advanced Materials (IAAM), and Linkoping University on the Baltic Sea from Stockholm-Helsinki-Stockholm by the Viking Line Cruise, M/S Mariella. The aim of the event is to cover the latest technology developments, applications, commercialization progress, end user requirements and challenges of Graphene and related 2D Materials.
A. Nouri; M. Mirzaei; T. Tayebi; Z. Alipanah
Abstract
In this work, density functional theory (DFT) calculations at the BLYP/6-31G* level was performed to investigate doping and functionalizing effect on the graphene in according geometric, NMR parameters and electronic properties. In the considered models, the energy gap is decreased in doped and functionalized ...
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In this work, density functional theory (DFT) calculations at the BLYP/6-31G* level was performed to investigate doping and functionalizing effect on the graphene in according geometric, NMR parameters and electronic properties. In the considered models, the energy gap is decreased in doped and functionalized models in respect to the pristine model but there are not significant changes between energy gap of the pristine model and functionalized models. Furthermore, results show the high and low sensitivity of the electronic properties of doped and functionalized models towards pristine model respectively. The results indicate that the formation energies of functionalized models are smaller than doped models ones. The NMR parameters follow the results of structural properties. It was found that for production of electronic devices doped models is better than functionalized models and nitrogen atom is a better choice for this purpose respect to the boron atom. All DFT calculations are performed by the Gaussian 98 package.
B. N. Patil; S. A. Acharya
Abstract
In the present work, ZnS-Gaphene (ZnS-GNS) composite was prepared by microwave irradiation method. The prepared samples were characterized by X-ray diffraction (XRD), to confirm the formation of GNS by reducing Graphite as well as ZnS-GNS nanocomposite. Raman spectroscopy identified D and G photon vibration ...
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In the present work, ZnS-Gaphene (ZnS-GNS) composite was prepared by microwave irradiation method. The prepared samples were characterized by X-ray diffraction (XRD), to confirm the formation of GNS by reducing Graphite as well as ZnS-GNS nanocomposite. Raman spectroscopy identified D and G photon vibration mode of GNS in the ZnS-GNS composite. X-ray photoelectrons spectra are also detected presence of graphene in ZnS. UV/VIS Spectra are studied for evaluation of photocatalytic activity. The composite is explored as photocatalysts to study dye degradation using methylene blue dye in aqueous slurry under irradiation of 663 nm wavelength. Under the same conditions the photocatalytic activity of the pure ZnS is also examined. The ZnS-GNS composite is found in enhancing the rate of photodegradation of toxic dyes as compared to pure ZnS. This Graphene based metal sulphide/oxide semiconductor nanocomposites are high potential material for Photo-degradation of toxic dyes, and act as good photocatalyst.
M. N. Muralidharan;Seema Ansari
Abstract
Optically triggered actuators offer unique advantages like wireless actuation and remote control when comared to other type of actuators. They are extremely useful where stimulus other than electricity or heat is preferred. Thermally reduced graphene oxide (TRGO)/thermoplastic polyurethane (TPU) composite ...
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Optically triggered actuators offer unique advantages like wireless actuation and remote control when comared to other type of actuators. They are extremely useful where stimulus other than electricity or heat is preferred. Thermally reduced graphene oxide (TRGO)/thermoplastic polyurethane (TPU) composite actuators were prepared by simple solution casting technique. The photomechanical actuation properties of the composites were studied under infrared illumination. It was found that the photomechanical response can be tuned by controlling the applied prestrain and the filler loading. Even with a low filler loading of 2 wt. % TRGO, the composite exhibited a very high photomechanical strain of 50.2% with an excellent stress of 1680 kPa at a prestrain of 220%. These high values were achieved at a very low light intensity of 16mWcm -2 . The high values of strain obtained with very good generative forces indicate that this is a promising material for light triggered actuators for many potential applications including robotics and biomedical devices.
Jyoti Tyagi;Rita Kakkar
Abstract
This review focuses on the applications of graphene, and the effects of doping and functionalization on its properties. Though known for several years, the potential applications of graphene in various fields have only been recently realized. Remarkable research is going on in the various application ...
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This review focuses on the applications of graphene, and the effects of doping and functionalization on its properties. Though known for several years, the potential applications of graphene in various fields have only been recently realized. Remarkable research is going on in the various application based fields of graphene, such as in hydrogen storage, Li batteries, catalysis and many more. Its use as a sensor to detect various species at the molecular level is fascinating. Also, on account of its 2D structure, graphene has found promising applications in several adsorption phenomena. Various adsorption studies have been done on the graphene surface resulting in the chemisorption of the chemical species. This review focuses on the application of graphene for removal of hazardous substances, such as heavy metal ions and drug metabolites, from waste waters. Another class of substances, known as disinfection by-products (DBPs), formed during the disinfection of drinking water using chlorine, ozone, chloramines and chlorine dioxide as disinfectants, and the use of graphene for their removal, is also discussed. Use of graphene based materials as chemical and biosensors and its applications in various other fields is also briefly discussed.
Anupama Chaturvedi; Ashutosh Tiwari; Atul Tiwari
Abstract
This communication describes the development of graphene and graphene reinforced polyvinylester nanocomposites. Low concentration of graphene was incorporated in the polymer matrix with the help of two different solvents. The role of solvent in the nanocomposite was studied. The FTIR spectroscopy and ...
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This communication describes the development of graphene and graphene reinforced polyvinylester nanocomposites. Low concentration of graphene was incorporated in the polymer matrix with the help of two different solvents. The role of solvent in the nanocomposite was studied. The FTIR spectroscopy and electron microscopy have supported the presence of graphene in the nanocomposites. It was discovered that vehicular medium (i.e., solvent) plays a vital role in the properties of the ultimate nanocomposites. When dimethylacetamide was used as solvent, the morphological analysis suggested the increased toughness while in case when tetrahydrofuran was used as solvent, nanocomposite appeared brittle in nature.
Mikael Syv
Abstract
The world of materials science is a fascinating dimension. Findings in materials which were first made many years ago may lead to new frontiers for energy technologies. In these days of increasingly urgent needs for environmental progress, it is a pleasure for a materials scientist to explore materials ...
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The world of materials science is a fascinating dimension. Findings in materials which were first made many years ago may lead to new frontiers for energy technologies. In these days of increasingly urgent needs for environmental progress, it is a pleasure for a materials scientist to explore materials concepts with potential advances in energy and environmental, or even biomedical, engineering. Already in 1907 it was observed that there could be light emission from an indirect bandgap material namely, carborundum which is an early name of silicon carbide. This observation is referred to as the first report of a light emitting diode. Now more than 100 years after, the silicon carbide is revisited to make a rare earth metal free white LED for general lighting purpose from new insightful perspectives regarding materials synthesis and growth technology implementation.
Atul Tiwari
Abstract
After decades, allots of research to exploit the unique properties of graphite resulted to a successful discovery of a new nano material called graphene. Unprecedented efforts by two Manchester University professors resulted in an extraction of a single layer of graphite in the year 2004 that earned ...
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After decades, allots of research to exploit the unique properties of graphite resulted to a successful discovery of a new nano material called graphene. Unprecedented efforts by two Manchester University professors resulted in an extraction of a single layer of graphite in the year 2004 that earned them a Nobel Prize of physics in 2010. Several terms that are interrelated to graphene such as graphite nano platelets, graphite oxide, single layer or few layers of graphite oxide, graphene oxide, functionalized graphene sheets or functionalized nano graphene sheets, exfoliated graphene oxide and their numerous processing techniques have appeared in the last few years.