Currently the preferred method for large-scale production of solution-processable graphene is via a nonconductive graphene oxide (GO) pathway, which uncontrollably cuts sheets into small pieces and/or introduces nanometer-sized holes in the basal plane. These structural changes significantly decrease some of graphene's remarkable electrical and mechanical properties. Here, we report an unpreced...

A variety of strategies for the synthesis of solution processable graphene sheets has been developed so far. However, no approach has been reported to directly produce highly conductive, low-oxygen-containing graphene sheets without relying on toxic reagents and metal containing compounds and without generating toxic by-products. With an aim of developing such an eco-friendly approach, for the ...

We consider the effect of atomic hydrogen exposure to a system of two undoped sheets of graphene grown near a silica surface (the first adsorbed to the surface and the second freestanding near the surface). In the absence of atomic hydrogen the van der Waals force between the sheets is attractive at all separations causing the sheets to come closer together. However, with addition of atomic hyd...

We report on the fabrication and measurement of devices designed to study the electrochemical behavior of individual monolayer graphene sheets as electrodes. We have examined both mechanically exfoliated and chemical vapor deposited (CVD) graphene. The effective device areas, determined from cyclic voltammetric measurements, show good agreement with the geometric area of the graphene sheets, in...

Tunnelling effect is a possible mechanism to explain the apparent large electric conductivity and nonlinear electric behavior of graphene-reinforced nanocomposites with polymer matrix. In this work, a numerical modeling framework is proposed to evaluate the effective electric conductivity in polymer composites reinforced with graphene sheets, taking into account the electrical tunnelling effect...

Flexible and ultratransparent conductors based on graphene sheets have been considered as one promising candidate for replacing currently used indium tin oxide films that are unlikely to satisfy future needs due to their increasing cost and losses in conductivity on bending. Here we demonstrate a simple and fast electrochemical method to exfoliate graphite into thin graphene sheets, mainly AB-s...

Graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of applications. A prerequisite for exploiting most proposed applications for graphene is the availability of processable graphene sheets in large quantities. The direct dispersion of hydrophobic graphite or graphene sheets in water without the assistance of dispersing agents has...

We report a new, simple, hydrazine-free, high-yield method for producing single-layer graphene sheets. Graphene sheets were formed from graphite oxide by reduction with simple deionized water at 95 °C under atmospheric pressure. Over 65% of the sheets are single graphene layers; the average sheet diameter is 300 nm. We speculate that dehydration of graphene oxide is the main mechanism for oxyge...

Tunnel effect is a possible mechanism to explain the apparent large electric conductivity and nonlinear electric behavior of graphene-reinforced nanocomposites with polymer matrix. In this work, a numerical modeling framework is proposed to evaluate the effective electric conductivity in polymer composites reinforced with graphene sheets, taking into account the electrical tunneling effect, whi...

We use first-principles calculations to investigate the geometric, electronic and magnetic properties of metal adatoms on two typical graphene substrates (monolayer and bilayer). Firstly, we study the adsorption behaviors and the doping effects of metal atoms on pristine and defective bilayer graphene sheets (PBG and DBG). It is found that the metal doping in DBG sheets is more stable than that...