Preparation and characterizations of nanoparticles from graphite via an electrochemically oxidizing method

Exfoliation of graphite was performed in ammonia medium via an electrochemically oxidizing method. Based on dynamic light scattering (DLS), transmission electron microscopy (TEM), selected area diffraction (SAD), X-ray diffraction (XRD), high resolution transmission electron microscopy (HREM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) measurements and elemental analysis, it was found that during electrolysis process graphite was exfoliated into particles of about 40 nm in diameter. These nanoparticles consist of multilayer and monolayer structures. The carbon sheets in these particles contain oxygen-containing groups derived from oxidization of graphite. Due to the presence of these polar groups, the nanoparticles can be readily dispersed in water and form a stable colloid. (C) 2003 Elsevier Science B.V. All rights reserved.