Graphitic C3N4 (g-C3N4) nanoparticles were prepared via a simple chemical synthesis route. The obtained g-C3N4 nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and ultraviolet-visible diffusive reflectance spectroscopy. The g-C3N4 nanoparticles showed a strong absorbance within visible light. The sonocatalytic performance of the g-C3N4 nanoparticles in degrading methylene blue (MB) was also investigated. Compared with commercial P25 nanoparticles. the g-C3N4 nanoparticles possessed a relatively better sonocatalytic activity. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.