Production of SiC Nanoparticles in Carbon Network by Pulsed Electrical Discharges in Liquid Hexamethyldisilazane with Gaseous Bubbles

Abstract

Discharges in liquid can efficiently produce nanoparticles via electrode erosion and (or) liquid decomposition. Although in-liquid spark discharges promote the erosion of electrodes, the injection of bubbles may enhance plasma-liquid interactions. In this study, we investigate the materials produced by sustaining pulsed discharges in liquid hexamethyldisilazane with injected Ar, He, or N2 gas bubbles. The electrical characteristics of the discharges are analyzed, and variations are detected between the materials produced using Ar or He gases and using N2. The behavior of the liquid medium after synthesis also exhibits differences, depending on the nature of the gaseous bubbles. For instance, the particles produced with Ar and He are rapidly (within hours) sedimented in the liquid medium, but those produced with N2 remain in suspension for several weeks. FTIR, Raman, TEM, and UV–Vis analyses show that the synthesized materials consist of SiC nanoparticles (~ 10 nm diameter) embedded in a hydrogenated carbonaceous structure with short-range order (~ 2 to 4 nm). O and N are detected in the structure, which indicates that the composition of the particles’ surface is complex. When the particles are heated at 600° C in air for 4 h, crystalline structures with a higher percentage of O and lower percentages of C and N are formed.