Formation of carbon bamboo-like nanostructures on silicon-containing nanoparticles

This study examines the morphology of material produced via arc discharge sputtering of a composite SiO2/C electrode in a helium medium under reduced pressure. The arc discharge causes evaporation of the anode material, with some products depositing on the cathode while others escape, creating a non-isothermal fan-shaped jet. Initial sputtered products include monatomic carbon and silicon, diatomic carbon particles, and carbon monoxide molecules. As the jet expands, cooling and condensation occur, leading to chemical reactions and nanostructure formation that deposits on collection screens. Materials were collected on the screens at various temperatures, revealing the formation of graphene, silicon carbide nanoparticles, bamboo-like carbon nanostructures, and distinct hollow carbon shells, depending on the temperature of the screen. Higher screen temperatures and reduced pressure promote the thermal decomposition of silicon carbide nanoparticles and the formation of bamboo-like carbon structures and distinct hollow carbon shells. The layering of carbon on silicon-containing nanoparticles generates stress, causing nanoparticles to be expelled from their carbon shells, which then reform into the bamboo-like carbon structures or distinct hollow carbon shells. Meanwhile, screens colder than 400 °C stabilize the deposited material and minimize physicochemical reactions. Thus, this work enhances our understanding of nanostructure formation through arc discharge sputtering and the influence of temperature and pressure conditions on material morphology. Graphical abstract