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A solution stabilization strategy that uses an easily removable media is critical to graphene (G) applications. Here, we demonstrate that highly stable graphene dispersions in low boiling point solvents such as isopropanol can be readily achieved by the uniform deposition of Ag nanoparticles (NPs) on the surface of graphene. Optimizing the synthesis parameters such as ultrasonic intensity, feeding...
Achieving stable suspensions of carbon nanotubes (CNTs) in water is still a challenge. Addition of surfactants is desirable as it allows keeping intact the intrinsic properties of the CNTs. However, for different applications, the potential toxicity of the surfactant is an important issue. Polysaccharides are among the best candidates and chemical modification can improve their intrinsic features...
The composites of V 2 O 3 –ordered mesoporous carbon (V 2 O 3 –OMC) were synthesized and used as anode materials for Li-ion intercalation. These materials exhibited large reversible capacity, high rate performance and excellent cycling stability. For instance, a reversible capacity of V 2 O 3 –OMC composites was 536mAhg −1 after 180cycles at...
Polymer composites reinforced by graphene platelets (GPLs) have the advantage of enhanced mechanical properties at low loadings. However the planar geometry of GPLs and their entanglement complicate the dispersion of graphene in the polymer matrix and limit the improvement of the mechanical properties. In this study, confocal Raman spectroscopic imaging was used to map the dispersion of GPLs in an...
Realizing mass production of graphene materials at low cost and high quality is urgently required for their real applications. Thermal exfoliation of graphite oxide (GO) is considered as a promising strategy though it normally requires a high exfoliation temperature together with a fast heating rate, making the produced graphenes suffer from high cost and concentrated topological defects. A mild exfoliation...
Graphene oxide (GO) based hydrogels were proposed to be used as biomaterials and stimuli-response materials, but their poor mechanical properties restricted their applications. We enhanced GO–poly(N-isopropylacrylamide) (PNIPAm) hydrogels by hybrid with the hectorite clay through in situ polymerization for the first time. This clay was found to stabilize the GO in the aqueous suspension when a reducer...
The development of metal-free catalyst for oxygen reduction reaction (ORR) is one of the most challenging tasks in fuel cells. Heteroatom doped graphenes have been recognized as the promising candidate. In this work, we have developed a one-pot hydrothermal approach towards three-dimensional nitrogen and sulfur co-doped graphene frameworks (N/S-GFs) employing graphene oxide and ammonium thiocyanate...
Commercial wood-based activated carbon was treated with hydrogen sulfide at 650 and 800°C to introduce sulfur to the carbon matrix. On the initial and S-doped samples adsorption of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel with equal molar concentrations of these species was measured at room temperature. The amount adsorbed increased with an increase in...
We report a lithium–air battery with a free-standing, highly porous Pd-modified carbon nanotube (Pd–CNT) sponge cathode. The Pd-CNT sponge was synthesized through a chemical vapor deposition growth followed with an electrochemical deposition process. To build a whole lithium–air battery, the air cathode is integrated with a ceramic electrolyte-protected lithium metal anode and non-volatile ionic liquid...
Few-layer graphene prepared from graphite exfoliated by chitosan has a preserved structure without oxidation or destruction of the sp 2 character of the carbon plane and exhibits a higher peroxidase catalytic activity than that of graphene oxide (GO) and its reduced form. The peroxidase catalytic activity of as-obtained few-layer graphene is 45 times higher than that of GO and 4 times higher...
Carbon nanotubes are known to obviate many limitations of classically employed conductors, but one finds it difficult to assemble them into macroscopic functional structures, like wires and cables, with appropriate performance. The employed protocols are usually problematic and not viable on a big scale. Herein, we show the durability of carbon nanotube wires (CNWs) obtained in a single step by the...
We have studied the interaction of CO with epitaxial graphene on Pt(111) and Ru(0001) by means of high-resolution electron energy loss spectroscopy measurements. Our experiments unambiguously demonstrate that in ultra-high vacuum conditions CO does not intercalate underneath the graphene monolayer supported on Pt(111) and Ru(0001). For submonolayer coverages of graphene on Pt(111), CO adsorption occurs...
The strategy to regularly arrange and join the polycyclic aromatic hydrocarbons of asphalt into graphene was explored. Expanded vermiculite with a multi-layered structure was used to adsorb asphaltene molecules onto its surfaces or into its interstices, and graphene sheets with 8–10 graphene layers and a width of tens of microns were obtained by carbonization of the regularly-arranged asphalt molecules...
Metal nanoparticle grafted graphene films (GFs) form a new composite for electron field emission devices. The GFs were deposited on Ni coated Si wafers by microwave plasma enhanced chemical vapour deposition. Graphene-based composites using Ti, Pd, Ag and Au were formed by thermal evaporation. The surface morphology and microstructure were probed by scanning and high resolution transmission electron...
Silver-nanoparticles-decorated reduced graphene oxide (rGO) was electrodeposited on indium tin oxide (ITO) by a cyclic voltammetry method. The results of X-ray diffraction, Fourier-transform infrared transmission spectroscopy and Raman spectroscopy confirmed the simultaneous formation of cubic phase silver nanoparticles and reduction of GO through the electrodeposition process. Field emission scanning...
We demonstrate the synthesis of single-layer graphene films on copper by photo-thermal chemical vapor deposition (PTCVD) realized using a rapid thermal processing system typically used in CMOS processing. Influence of the temperature on the low-pressure (10mbar) graphene synthesis using methane precursor was characterized by analyzing the crystalline quality, thickness and electronic properties of...
To explore the role of the interaction between the adsorbed molecules and substrates for the charge transfer (CT) induced Raman enhancement, we systematically study the surface enhanced Raman scattering (SERS) on graphene, graphene oxide (GO) and reduced graphene oxide (r-GO) using rhodamine 6G (R6G) as the probe molecule. The Raman spectra of R6G molecules deposited on these three SERS substrates...
The intercalation of N,N,N′,N′-tetramethyl-ethane-1,2-diamine (tmeda) into C 6 Li derived from papyex, a partially oriented graphite foil, results in the co-presence of two ternary phases having out-of-plane (c-axis) identity periods of 11.5 and 9.1Å. As we reported for the powdered sample prepared using a natural graphite source, these distances are associated with two tmeda orientations...
We employed a homogenizing method to disperse silver nanorods onto graphene nanosheets (GNs) in liquid phase, forming a three-dimensional Ag/GN framework. The Ag/GN hybrid material was used to investigate Li-ion insertion/extraction properties. A microwave-assisted polyol approach was adopted to synthesize highly crystalline Ag nanorods. The as-prepared Ag/GN hybrid anode shows improved Li-storage...
Controlled growth and uniform patterning of graphene/carbon shells encapsulated gold nanoparticles (GNPs) on silicon wafer or on high curvature carbon nanotubes (CNTs) is reported here. This was achieved by utilizing patterned gold nanoparticles with controlled sizes (∼30–600nm) via gold film dewetting process. Surface-oxidized and patterned nanoparticles were used as sacrificial catalysts for the...
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