Raman characterization and UV optical absorption studies of surface plasmon resonance in multishell nanographite

Nanographite (NG) particles were produced by annealing of superpurified detonation nanodiamonds (grain size -5 nm) at 1600 degrees C. The aim of this research was to provide Raman characterization of nanographites obtained and to investigate characteristic features of UV optical absorption in NC suspensions caused by the excitation of surface plasmon resonance (SPR) and its dependence on disorder and defectiveness of graphene shells during their transformation. The 1-st and 2-nd order Raman spectra of the NC samples excited at 514 nm were analyzed. Two different approaches applied for evaluation of the in-plane NC crystallite sizes by using the D- and G-band intensities ratio gave quite different results (similar to 3.5 nm and similar to 5.5 nm) reflecting, most likely, a complicated NC structure. The changes in both intensity and position of SPR absorption peak for water suspension of NC particles may originate in structural imperfections and/or changes in aggregation of NC particles. (C) 2010 Elsevier B.V. All rights reserved.