Efficient and green synthesis of SiOC nanoparticles at near-ambient conditions by liquid-phase plasma

Si-based ceramics such as silicon oxycarbide (SiOC) exhibit inimitable electrical, thermal, chemical, mechanical, and biological properties and have attracted interest for a wide range of technological applications. Recently, considerable efforts have been made to improve the conventional approach to produce Si-based ceramics that requires extreme environments and cannot be directly used to form the particles on a nanosize scale. In this study, we demonstrate that SiOC nanoparticles (NPs) with a crystalline phase can be synthesized at atmospheric pressure in a gas bubble discharge in liquid hexamethyldisiloxane. The as-prepared nanoparticles exhibit a carbon-free and highly crystalline structure of SiC. The mechanism of the formation of SiOC NPs was systematically studied, providing an in-depth understanding of the formation of SiOC NPs and insight on the way to control the structures of Si-based ceramic NPs. This novel approach offers a simple, efficient, and green route for the production of SiOC NPs and has great potential to produce such nanomaterials on a large scale.