One-Pot Sonochemical Synthesis of Carbon Nano-Onions from Silicon Carbide in Pure Water

Abstract

Carbon nanomaterials are a class of low-dimensional materials that have aroused a great deal of interest for decades. Carbon nano-onions (CNOs) are carbon nanomaterials with a wide range of applications. In this study, we report a novel process for synthesizing CNOs from SiC—the only inorganic carbon source—through one-pot sonication in pure water at room temperature. This synthesis process is more facile and can be performed under gentler conditions and lower temperatures than previous methods. The as-synthesized samples were characterized using transmission electron microscopy (TEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and scanning transmission electron microscopy–electron energy loss spectroscopy (STEM-EELS). The TEM results revealed CNOs with diameters of approximately 20–30 nm, and the FTIR and STEM-EELS results indicated the presence of oxygen-containing functional groups on the CNOs and the growth of carbon from a SiC single crystal. The proposed method for obtaining CNOs from an inorganic carbon source via sonication provides novel insights into the CNO generation mechanism and its functionalization.