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Inspired by a very recent theoretical work on penta-graphene, a two dimensional (2D) carbon sheet [Proc. Nat. Acad. Sci. 2015, 112, 2372] composed of only carbon pentagons, we have made an attempt to see the stability and electronic properties of its one dimensional (1D) ribbons, naming penta-graphene nanoribbon (pentaGNR). Our first principle calculations predict that, pentaGNR is dynamically stable;...
Since graphene, a representative 2-dimensional crystal, has an extreme surface-to-volume ratio, its various material properties are known to be susceptible to various interactions with environment. Its high stretchability, in particular, allows graphene to conform well to external perturbation, which leads to modifications of its electronic, magnetic and chemical properties. In this work, we report...
A nanosecond-resolution pulse-heating technique was used to measure thermal expansion of pyrolytic graphite specimens. The change in the specimen volume was directly measured by means of a laser interferometer. The dependence of density of the graphite on specific enthalpy as well as the change in the specific volume upon melting has been measured at the pressures of 0.4–2 GPa. We have found that...
A new hydrocarbon – hydrographite – with the composition close to CH is shown to form from graphite and gaseous hydrogen at pressures above 2 GPa and temperatures from 450 to 700 °C. Hydrographite is a black solid thermally stable under ambient conditions. If heated in vacuum, it decomposes into graphite and molecular hydrogen at temperatures from 500 to 650 °C. Powder X-ray diffraction characterizes...
The assessment of the biodegradability potential of carbon nanotubes (CNTs) is a fundamental point towards their applications in materials science and biomedicine. Due to the continuous concerns about the fate of such type of nanomaterials, it is very important to understand if they can undergo degradation under certain conditions and if the morphology and structure of the nanotubes play a role in...
Activated graphene (AG) possesses high conductivity and large specific surface area (SSA), but suffers from ultralow yield and limited packing density. Therefore, the incorporation of activated pyrolytic carbon (AC) and (activated) graphene provides an alternative solution. Here, a novel and facile method combining electrostatic-assistant carbonization and KOH activation is adopted to prepare regularly-constructed...
Hybrid graphene aerogels (HGA) consisting of graphene oxide (GO) and graphene nanoplatelets (GNP) were prepared and introduced into polyethylene glycol (PEG) via vacuum impregnation, aiming at obtaining composite phase change materials (PCMs) with high thermal conductivity, outstanding shape-stabilization, high energy storage density, commendable thermal repeatability and the ability to light-to-heat...
The low energy density of graphene-based supercapacitors has been a critical bottleneck for their commercialization. In particular, the poor capacitance due to the lack of electrically porous channels and insufficient Faradaic reactions in reduced graphene oxide (RGO) electrodes has been a major limiting factor for their successful application. Herein, we demonstrate an innovative process for modifying...
A simple wet chemical method has been used to prepare MoSx in situ grown on graphene oxide (MoSx/GO) as a highly active and stable electrocatalyst for hydrogen evolution reaction (HER). The role of the oxygen-containing functional group on the surface of GO with different oxidation degrees have been studied for obtaining MoSx/GO with excellent electrochemical activity for HER. The electrochemical...
Carbon nanomaterials (carbon nanotubes (CNTs) and graphene) are promising materials for optoelectronic applications, including flexible transparent and conductive films (TCFs) due to their extraordinary electrical, optical and mechanical properties. However, the performance of CNT- or graphene-only TCFs still needs to be improved. One way to enhance the optoelectrical properties of TCFs is to hybridize...
Large regions of pristine graphene are essential to applications which rely on the ideal graphene properties. Common methods for transferring chemical vapour deposition grown graphene to suitable substrates leaves metal oxide particles and poly(methyl methacrylate) (PMMA) residues on opposing surfaces, which degrade the properties. A common method to reduce the residues include annealing in vacuum...
Negative refraction medium can in principle be realized using artificial composites composed of semiconductor/metallic inclusions, which experience negative refraction over certain frequency region due to structural resonant. It would be desirable if we could extend negative refraction to alternative natural semimetal candidates. Here, we show that by employing multilayer-graphene and cubic boron...
This paper reports on a comparative study of the electronic properties of ultra-thin film of NiO(100)/Ni(111) and graphene/Ni(111) intercalated with oxygen atoms. A way to combine a high quality CVD-grown graphene and a reduced interaction with the supporting substrate is to insert atomic species underneath carbon layer. Moreover, the intercalation of oxygen atoms allows, in some condition, to obtain...
Mechanical properties of bilayer graphene/poly(methyl methacrylate) (GR/PMMA) and reference PMMA thin films are investigated using various macro, micro and nano mechanical test methods. The GR/PMMA bilayer film consists of the CVD graphene layer (1 nm thick) spin coated with 1 μm thick PMMA layer. Small punch test, Berkovich nanoindentation, AFM nanoindentation, AFM nanoscratch, and spherical-conical...
We perform comprehensive first-principles calculations to study the addition pattern in multiply functionalized carbon nanotubes. We evaluate the relative strength of the rivaling forces between electronic effect and steric hindrance that determine whether the “cooperative addition” or the “random addition” takes place for monovalent or divalent functionalizations. We find that the electronic effect...
Highly oriented pyrolytic graphite (HOPG) and monolayer graphene were irradiated by swift heavy ions (SHI, 479 MeV 86Kr and 250 MeV 112Sn) and highly charged ions (HCI, 4 MeV 86Kr19+). The irradiation effects caused by different types of irradiation were investigated by Raman spectroscopy. It was found that the intensity ratio of D peak to G peak (ID/IG) in the case of HCI was higher than that of...
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