Raman spectroscopy of carbon nano-particles synthesized by laser ablation of graphite in water
J.F. Cardenas, T. Cadenbach, Z.-B. Zhang, C. Costa-Vera, A. Debut, A.V. Vaca, S.-L. Zhang, and J.L. Paz
Carbon nanoparticles (CNPs) have been synthesized by laser ablation of polycrystalline graphite in water using a pulsed Nd:YAG laser (1064 nm) with a width of 8 ns. Structural and mesoscopic characterization of the CNPs in the supernatant by Raman spectroscopy provide evidence for the presence of mainly two ranges of particle sizes: 1-5 nm and 10-50 nm corresponding to amorphous carbon and graphite NPs, respectively. These results are corroborated by complementary characterization using atomic force microscopy (AFM) and transmission electron microscopy (TEM). In addition, large (10-100 µm) graphite particles removed from the surface are essentially unmodified (in structure and topology) by the laser as confirmed by Raman analysis.