In the present work, the free vibration behavior of rectangular graphene sheet under shear in-plane load is studied. Nonlocal elasticity theory has been implemented to study the vibration analysis of orthotropic single-layered graphene sheets (SLGSs) subjected to shear in-plane load. The SLGSs is embedded on a viscoelastic medium which is simulated as a Visco-Pasternak foundation. Using the pri...

Self-assembly of metal phthalocyanine (MPc) molecules on monolayer graphene (MG) epitaxially grown on Ru(0001) and Pt(111) is investigated by means of lowtemperature scanning tunneling microscopy. At low coverage, dispersive single molecules, dispersive molecular chains, and small patches of Kagome lattice are observed for iron phthalocyanine (FePc), manganese phthalocyanine (MnPc), nickel phth...

Since Geim and Novoselov’s successful production of high quality graphene, its unique properties have found a number of applications. But graphene is not an exotic chemical compound; instead, it is a sheet of graphite, one atom think. Before 2008, the only way to produce graphene was through successive pealing of graphite with scotch tape until graphite flakes as thin as 1 atomic layer were lef...

We show that edge stresses introduce intrinsic ripples in freestanding graphene sheets even in the absence of any thermal effects. Compressive edge stresses along zigzag and armchair edges of the sheet cause out-of-plane warping to attain several degenerate mode shapes. Based on elastic plate theory, we identify scaling laws for the amplitude and penetration depth of edge ripples as a function ...

Graphene oxide (GO) sheets with controlled species of oxygen-containing groups are important for fabricating graphene materials with desired structures and properties. Here we report a water-addition modified Hummers method to prepare GO sheets with tunable amounts of hydroxyl and epoxide groups without destroying their structural integrity. This method is simple, effective, and efficient. It c...

Intercalation of Pb at graphene/Ru(0001) interfaces has been dynamically observed using in situ low energy electron microscopy and photoemission electron microscopy. A comparative study of Pb intercalation on the submonolayer and complete monolayer graphene surfaces suggest that the Pb intercalation happens through the open edges of graphene islands, starting at around 150 °C. Spatially-resolve...

Electrocatalysis of oxygen reduction using Pt nanoparticles supported on functionalized graphene sheets (FGSs) was studied. FGSs were prepared by thermal expansion of graphite oxide. Pt nanoparticles with average diameter of 2 nm were uniformly loaded on FGSs by impregnation methods. Pt-FGS showed a higher electrochemical surface area and oxygen reduction activity with improved stability as com...

We have developed an unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sps and sp models up to firstand second-nearest neighbors, respectively. Our results show that the Si graphene-like sheets considered here are metals or zerogap semiconductors, and...

In this work, reduced graphene oxide (RGO) sheets are successfully introduced into the conductive polypyrrole (PPy) matrix as conductive channels and co-catalyst, through simple incorporation of graphene oxide (GO) into PPy and subsequent in situ reduction from GO/PPy to RGO/PPy composite film. The RGO/PPy film is fabricated as a counter electrode for dye-sensitized solar cells, and it exhibits...

Exposure of highly oriented pyrolytic graphite to bromine vapor gives rise to in-plane charge conductivities which increase monotonically with intercalation time toward values for 6 at % Br that are significantly higher than Cu at temperatures down to 5 K. Magnetotransport, optical reflectivity and magnetic susceptibility measurements confirm that the Br dopes the graphene sheets with holes whi...