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Corrosion of metals causes tremendous financial loss and disasters every year. Graphene is a promising candidate for anti-corrosion coating, due to its unique properties, e.g. chemical inertness, impermeability and high conductivity. Despite being a commercially important material, it is difficult to grow graphene on carbon steels and is therefore prominently grown on copper or nickel substrates....
A theoretical model supported by experimental results explains the dependence of the Raman scattering signal on the evolution of structural parameters along the amorphization trajectory of polycrystalline graphene systems. Four parameters rule the scattering efficiencies, two structural and two related to the scattering dynamics. With the crystallite sizes previously defined from X-ray diffraction...
We report helium diffraction from graphene grown by chemical vapour deposition (CVD) using copper foil. This method reveals acoustic phonons, which are physically important to thermal conductance as well as a sensitive probe of graphene's interactions with the underlying substrate. Helium diffraction is made possible by the high quality of graphene produced by a recently reported “peel-off method”...
SiC-assisted growth of tubular graphenic cones (TGCs) with carbon nanotube tip is achieved with high yield in the microwave plasma chemical vapor deposition process. No pre-existing metal or semiconductor catalyst particles are required on the substrate prior to the deposition process. Instead, the in situ grown SiC crystallites serve as the catalyst for the growth of TGCs. Thanks to the easy formation...
In this study, the impact of graphene sheet size on the electrical conductivity of interconnected graphene foam polymer composite is thoroughly investigated. Graphene oxide solution is produced from small flake graphite (SFG) (2–15 μm) and large flake graphite (LFG) (>100 μm), respectively. Each solution is used to produce three-dimensional GO foam, which is subsequently heat-treated to produce...
The literature reveals that ferromagnetism in zinc peroxide (ZnO2) is due to the exchange interaction between localized electron spin moments resulting from oxygen vacancies at the surface of nanoparticles, while in graphene may be due to existence of various defects. However ZnO2 show paramagnetic behaviour, whereas graphene exhibits very low magnetic intensity (0.0004 emu g−1). To enhance magnetization,...
Graphene can be obtained via sonication-assisted liquid-phase exfoliation, but the production rate of few-layer graphene (FLG) is still low. A high-power probe sonicator was used in this study to improve the production rate of FLG, and its performance was optimized by controlling processing parameters such as the initial graphite concentration, surfactant concentration and liquid volume. By optimizing...
Graphene aerogels derived from graphene-oxide (GO) starting materials recently have been shown to exhibit a combination of high electrical conductivity, chemical stability, and low cost that has enabled a range of electrochemical applications. Standard synthesis protocols for manufacturing graphene aerogels require the use of sol–gel chemical reactions that are maintained at high temperatures for...
A hybrid featuring the CuInS2 quantum dots (CuInS2-QDs) on reduced graphene oxide (rGO) sheets is synthesized by a facile one-pot solvothermal approach with thiourea as S source, in which graphene oxide (GO) sheets are reduced into rGO sheets in course of the CuInS2-QDs aggregate growth. The growth mechanism of the hybrid is elucidated. It is found that adsorption of Cu2+ cations mainly takes place...
Recently, hexagonal boron nitride (h-BN) has been shown to act as an ideal substrate to graphene by greatly improving the material transport properties thanks to its atomically flat surface, low interlayer electronic coupling and almost perfect reticular matching [1]. Chemical vapour deposition (CVD) is presently considered the most scalable approach to grow graphene directly on h-BN. However, for...
The mechanisms for oxygen etching of graphene on Ir(111) are uncovered through a systematic variation of the graphene morphology – ranging from an impermeable graphene layer to graphene nanoflakes – and the application of complementary experimental methods, including scanning tunneling microscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption. Associated with a strong variation...
Carbon-based nanomaterials (CNMs) such as graphene and carbon nanotubes (CNTs) have huge potential in environment and energy related applications. Although a wide range of synthesis methods has been developed to produce CNMs, green synthesis methods with either energy-saving reactions or inexpensive starting materials are gaining more attentions recently. It is evident from recent developments that...
The oxidative carbon removal from Cu foils was systematically studied together with the resulting suppression of the graphene flake nucleation during subsequent chemical vapor deposition (CVD). The carbon content was determined by segregating bulk dissolved carbon during a special rapid cooling process towards the surface, where it was detected by x-ray photoelectron spectroscopy. After exposure to...
With the development of terahertz (THz) anti-radar technology, the demands for new antireflection coating technology and materials based on impedance matching mechanism have increased significantly. Herein, the reflection impedance matching properties of p-polarized THz wave at a randomly stacked multi-layer graphene interface is studied using both experiment and theory at oblique incidence. The experiment...
A proper design of heterogeneous molecular catalysts supported on carbon materials requires a systematic study of “metal–carbon support interactions” and their influence on catalytic activity. In this study, hybrid materials containing covalently anchored iridium N-heterocyclic carbene (NHC) organometallic complexes have been successfully prepared from oxidized and partially reduced carbon nanotubes...
Graphene growth on a substrate has been widely investigated due to its broad application potential. Previous studies have found that the properties of graphene depend on its underlying substrate and their interaction. However, the dynamic behavior of the interfacial structure as a function of temperature has not been investigated, as well as the interfacial structure related to its mechanical properties...
Production of large quantities of graphene sheets with less than 10 layers is extremely difficult due to the lack of a controllable process and method to separate multilayered graphene. Here, we demonstrate a controllable and scalable aqueous arc discharge process that produces high quality bi- and trilayers of graphene. With this process, the number of stacked graphene layers is controlled by adjusting...
The effects of humidity on the electronic properties of mono- and bi-layer graphene prepared by chemical vapour deposition and transferred on SiO2 are investigated via simultaneous global transport and local work function measurements using the van der Pauw method and Kelvin probe force microscopy, respectively. It is found that mono-layer graphene on SiO2 is extremely sensitive to water vapour, with...
Graphene is a layer of sp2 hybridized carbon of a single-atomic thickness, which exposes most of its atoms to the surrounding medium. The properties of graphene are highly dependent on its number of layers. Currently, the synthesis of uniform graphene with a specific number of layers in a controllable way is rather hard. In this review, we present the highlights of current advances regarding utilization...
In this paper, aligned graphene sheets (AGS) embedded in PDMS (AGS@PDMS) has been prepared by repeated spin-coating (SC) technique. The triboelectric nanogenerator (TENG) based on the AGS@PDMS film is fabricated and its electric output is investigated systematically with different contents of filling graphene sheets and different spin-coating layers. The PDMS embedded with AGS is compared with that...
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