Preparation of SiC/SiO2 core–shell nanowires via molten salt mediated carbothermal reduction route

•SiC nanowires were prepared from low cost silica fume and sucrose.•The morphology of nanowires is bamboo-like shape.•The nanowires exhibit a significant blue shift.

The growth of silicon carbide (SiC) crystal generally requires a high temperature, especially when low quality industrial wastes are used as the starting raw materials. In this work, SiC/SiO2 core–shell nanowires (NWs) were synthesized from low cost silica fume and sucrose via a molten salt mediated carbothermal reduction (CR) route. The molten salt was found to be effective in promoting the SiC growth and lowering the synthesis temperature. The resultant NWs exhibited a heterostructure composed of a 3C–SiC core of 100 nm in diameter and a 5–10 nm thick amorphous SiO2 shell layer. The photoluminescence spectrum of the achieved SiC NWs displayed a significant blue shift (a dominant luminescence at round 422 nm), which suggested that they were high quality and could be a promising candidate material for future optoelectronic applications.