High-Yield Synthesis of SiC@SiO₂ Core–Shell Nanowires on Graphite Substrates for Energy Applications

Abstract

High-purity silicon carbide @ silicon oxide core− shell nanowires (SiC@SiO 2 NWs) were prepared on graphite substrates by a thermal evaporation method. Amorphous SiO 2 coats with high chemical activity were obtained on the surface of silicon powders by wet oxidation. The effects of the oxidation time of silicon powders on the morphology and productivity of SiC@ SiO 2 NWs were investigated. The growth of SiC@SiO 2 NWs follows the vapor−solid pattern, and the growth mechanism has been elucidated. The results showed that the yield of SiC@SiO 2 NWs was enhanced by ∼654% with the wet oxidized silicon source compared to the preoxidation. The morphology and thickness of SiO 2 coats play an important role in the yield and stacking fault (SF) density of SiC@SiO 2 NWs. This work provides a feasible and optimal process for the preparation of high-yield SiC@SiO 2 NWs.