Latest articles in this journal
Graphene, Volume 3, pp 44-50; https://doi.org/10.1166/graph.2015.1059
This paper reports synthesis procedure for few-layer graphene (FLG) on silicon carbide (SiC) at relatively lower temperature (300 °C), as compared to the temperature for graphene synthesis on non-metal surfaces reported to date, using microwave plasma chemical vapor deposition. The results demonstrate that 3 to 4 layer graphene films can be produced within two minutes on a SiC substrate. The graphene domain size and coverage are observed to depend on the terminal element of the SiC surface. Electrical characterization reveals that the films contain structural defects. Room temperature mobility of 75 cm2 V–1 s–1 and carrier density of 4.8 × 1016 cm–2 were found on the Si-terminated face. The carrier concentration was lower (1.2 × 1013 cm–2) for the FLG grown on the C-terminated surface. FLG thus grown exhibits p-type behavior. The presented plasma assisted direct growth of graphene on SiC at low temperatures is attractive for high-throughput graphene production.
Graphene, Volume 3, pp 61-64; https://doi.org/10.1166/graph.2015.1062
High-pressure hydrogen storage property of both platinum and nickel nanoparticles decorated functionalized hydrogen exfoliated graphene is investigated using Sieverts apparatus. The hydrogen uptake of Pt/Ni/f-HEG is 1.8 wt% at 2 MPa and 303 K. The hydrogen uptake capacity of Pt/Ni/f-HEG exceeds the physisorption capacity of pristine hydrogen exfoliated graphene. The results imply that the hydrogen storage capacity of Pt/Ni/f-HEG is via spillover mechanism.
Graphene, Volume 3, pp 65-71; https://doi.org/10.1166/graph.2015.1061
The carboxylic acid functionalized single-walled carbon nanotubes (SWCNTs) were uniformly distributed in polyurethane (PU) matrix by covalent bonding between carboxyl, diisocyanate and trimethylol propane (TMP) groups to form urethane linkage. The TMP was used as a crosslinker to form three dimensional nanonetworks. The PU based nanocomposites exhibit open cell structure could be useful for synthetic leather. The peaks in the range of 2800–3059 cm–1 (C–H), 3250–3400 cm–1 (N–H) and, 1730 cm–1 (C=O) were conform PU by FT-IR spectroscopy. The Raman spectra were investigated on polyurethane/SWCNTs to determine sp 2 carbon centres of disorder band (D-band) at 1313 cm–1 and tangential band (G-band) at 1542 cm–1. Loading of f-SWCNTs into polymer matrix, thermal stability drastically increased up to 466 °C. The mechanical properties of the composites facilitate to improve the tensile strength, Young's modulus and % elongation at break. These nanocomposites could be used for coating application.
Graphene, Volume 3, pp 25-28; https://doi.org/10.1166/graph.2015.1058
Reduced graphite oxide (RGO) is a versatile materials used for developing products in various commercial applications. Graphite oxide (GO) materials were prepared by well known modified hummer's method. RGO and RGO cakes were obtained by the chemical reduction of GO using hydrazine hydrate at room temperature. The obtained RGO product was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscope (SEM), Raman techniques. This is an efficient route to produce RGO sheets and amenable to bulk production and for commercial applications.
Graphene, Volume 3, pp 40-43; https://doi.org/10.1166/graph.2015.1053
Graphene, Volume 3, pp 51-55; https://doi.org/10.1166/graph.2015.1055
With the advent of Industrial Revolution, Pollution of water resources has become a major concern for world community. Major pollution causing industrial effluents such as Leather Tannery effluents, Textile dyes etc. contain one of the most toxic heavy metal Chromium ions and the removal of such contaminant is considered to be a major hurdle in environmental remediation. Graphene Oxide has been known to be used in removal of heavy metals in previous works. Graphene oxide was reduced and functionalized by an eco-friendly method using Diferuloyl Methane Analog, a polyphenol resembling the natural curcumin. The product, i.e., functionalized reduced-Graphene Oxide was characterized by X-ray Diffraction, Scanning Electron Microscopy, Fourier Transform Infra Red Spectroscopy to ascertain the conjugate is formed. Finally, adsorption studies of Chromium ions by Graphene Oxide and Diferuloylmethane analog Functionalized Graphene Oxide was carried out using Column Chromatography technique both qualitatively and quantitatively and the efficiency of Diferuloylmethane analog Functionalized and Reduced Graphene Oxide was established. The efficacy was analyzed by Atomic Adsorption Spectroscopy and the results were compared in various concentrations using graphical representation. We conclude that the functionalized reduced-graphene oxide effectively adsorb chromium in comparison with unfunctionalized graphene oxide.
Graphene, Volume 3, pp 34-39; https://doi.org/10.1166/graph.2015.1052
Graphene, Volume 3, pp 16-24; https://doi.org/10.1166/graph.2015.1054
Graphene, Volume 3, pp 6-15; https://doi.org/10.1166/graph.2015.1057
A single quantum well (SQW) p–n junction diode structure based on graphene nanoribbon (GNR) has been proposed in this paper and its quantum mechanical properties have been investigated under reverse bias by obtaining the self-consistent solution of coupled Schrödinger and Poisson equations. The quantum confinement of both electrons and holes within the quantum wells associated with conduction and valance bands of SQW GNR p–n diode has been studied. A theory has also been developed for interband tunneling in the SQW GNR p–n junction diode. The Zener tunneling probability of reverse biased SQW GNR p–n junction diode has been calculated starting from the intrinsic bandstructure of GNR by evaluating the Wentzel-Kramer-Brillouin (WKB) band-to-band tunneling probability.
Graphene, Volume 3, pp 56-60; https://doi.org/10.1166/graph.2015.1060