The groundbreaking discovery1 that graphite could be cleaved into its 2D building block, graphene, has led to similar efforts directed towards other layered 3D solids. In fact, a wide variety of 2D materials have been discovered over the past decade: phosphorene, transition metal dichalcogenides and MXenes (transition metal carbides, nitrides or carbonitrides) to name just a few2,3. Most such 2...

A solid exfoliation method is developed for the synthesis of single- or few-layered (≤5 layers) graphene by ball milling of graphite with ammonia borane. Nearly quantitative yield in which ca. 25% is single-layered graphene can be obtained. We believe that this highly efficient method will offer a facile approach for the preparation of high quality and large quantity graphene.

Graphite intercalation compounds are formed by inserting guest molecules or ions between sp(2)-bonded carbon layers. These compounds are interesting as synthetic metals and as precursors to graphene. For many decades it has been thought that graphite intercalation must involve host-guest charge transfer, resulting in partial oxidation, reduction or covalent modification of the graphene sheets. ...

Loose graphene sheets, one to a few atomic layers thick, are often observed on freshly cleaved HOPG surfaces. A straightforward technique using electrostatic attraction is demonstrated to transfer these graphene sheets to a selected substrate. Sheets from one to 22 layers thick have been transferred by this method. One sheet after initial deposition is measured by atomic force microscopy to be ...

The dispersion behavior of graphene oxide in different organic solvents has been investigated. As-prepared graphite oxide could be dispersed in N, N-dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran, and ethylene glycol. In all of these solvents, full exfoliation of the graphite oxide material into individual, single-layer graphene oxide sheets was achieved by sonication. The graphene ...

We report a high-throughput method of generating graphene monolayer (>90% yield) from weakly oxidized, poorly dispersed graphite oxide (GO) aggregates. These large-sized GO aggregates consist of multilayer graphite flakes which are oxidized on the outer layers, while the inner layers consist of pristine or mildly oxidized graphene sheets. Intercalation-exfoliation of these GO aggregates by tetr...

Graphene and its composite hydrogels with interconnected three-dimensional (3D) structure have raised continuous attention in energy storage. Herein, we describe a simple hydrothermal strategy to synthesize 3D CoS/graphene composite hydrogel (CGH), which contains the reduction of GO sheets and anchoring of CoS nanoparticles on graphene sheets. The formed special 3D structure endows this composi...

We report a facile and low-cost method to directly exfoliate graphite powders into large-size, high-quality, and solution-dispersible few-layer graphene sheets. In this method, aqueous mixtures of graphite and inorganic salts such as NaCl and CuCl2 are stirred, and subsequently dried by evaporation. Finally, the mixture powders are dispersed into an orthogonal organic solvent solution of the sa...

Three-dimensional graphene (3DG) sponge has attracted increasing attention because it 10 combines the unique properties of cellular materials and the excellent performance of graphene. 11 The preparation of 3DG sponge depends mainly on the self-assembly of graphene oxide sheets. 12 Here, we demonstrate facile fabrication of 3DG sponge with a large-scale and ordered porous 13 structure, exploiti...

Angle-resolved photoemission and x-ray diffraction experiments show that multilayer epitaxial graphene grown on the SiC(0001) surface is a new form of carbon that is composed of effectively isolated graphene sheets. The unique rotational stacking of these films causes adjacent graphene layers to electronically decouple leading to a set of nearly independent linearly dispersing bands (Dirac cone...