in this study ptfeco ternary alloys nanoparticles of three dimentional (3d) rhombus shapes dispersed on graphene nanosheets (ptfeco/gr) were successfully prepared and studied as electrocatalysts for oxygen reduction reaction (orr) in polymer-electrolyte fuel cells. a combination of analytical techniques including powder x-ray diffraction, x-ray photoelectron spectra, inductively coupled plasma-...

graphene sheet including single vacancy, double vacancy and stone-wales with armchair and zigzag structure was simulated using molecular dynamics simulation. the effect of defects on shear’s modulus, shear strength and fracture  strain was investigated. results showed that these shear properties reduce when the degrees of all kinds of defects increase. the dangling bond in sv and dv defected gr...

this paper presents the thermal vibration analysis of double-layer graphene sheet embedded in polymer elastic medium, using the plate theory and nonlocal continuum mechanics for small scale effects. the graphene is modeled based on continuum plate theory and the axial stress caused by the thermal effects is also considered. nonlocal governing equations of motion for this double-layer graphene s...

in the present work, graphene was synthesized by chemical vapor deposition (cvd) method. the structure of graphene was then confirmed by x-ray diffraction (xrd) and scanning electron microscope (tem) images. after that, mixed acid method (h2so4/hno3) was used to make the structure of synthesized graphenehydrophilic. in this method, carboxylate and hydroxide groups were linked to the edges of gr...

nano-graphene oxide was synthesized by the oxidation of graphite powders. the structural nature of the nano-graphene oxide was characterized by a variety of techniques including xrd, tem, ft-ir and uv/vis. the functional groups on its basal planes and edges of nano-grahene oxide play important role in catalytic activity. the catalytic activity of nano-graphene oxide was investigated on crossed-...

Free vibration and wave analysis of thick rectangular graphene are studied by employing the propagation method. To consider small-scale effects thickness a plate in nanoscales, equations motions represented Eringen nonlocal theory coupled with Mindlin plates. solve governing motion technique, reflection matrices derived. These combined to obtain exact natural frequencies sheets for all six poss...

graphene modified glassy carbon electrodes have been developed for the determination of calcium dobesilate in pharmaceutical formulations. the prepared graphene and cnts were used as a conductive substrate for electrochemical study of calcium dobesilate. the direct electrochemistry of calcium dobesilate showed a reversible cyclic voltammogram with a formal potential of 133 mv (vs. ag/agcl) for ...

Piezoelectric quasicrystals have attracted extensive attention due to their unique physical and mechanical properties. This paper studies the dynamic response of multilayered two-dimensional decagonal piezoelectric quasicrystal sector plates with imperfect interfaces. Based on linear elasticity, partial differential state equations along thickness direction are derived by using state-space meth...

in the present study, the effect of various weight fractions of graphene nanoplatelet (gpl) on flexural fatigue behavior of epoxy polymer has been investigated at room temperature and generally the temperature was monitored on the surface of specimen during each test. the flexural stiffness of grapheme nano-platelet/epoxy nanocomposites at 0.1, 0.25 and 0.5 wt. % as a main effective parameter o...