One-step molten-salt-mediated preparation and luminescent properties of ultra-long SiC/SiO2 core–shell nanowires

Ultra-long SiC/SiO2 core–shell nanowires were successfully prepared on a graphite felt with Ni(NO3)2 coating by a straightforward molten-salt-mediated carbothermal reduction route using silica fume and phenolic resin as starting materials at 1400 °C. The as-synthesized nanowires, 150–500 nm in diameter and up to several hundred microns in length, comprised a crystalline 3C–SiC core with a thin amorphous SiO2 shell (about 30 nm). The growth mechanism of the as-synthesized nanowires was most likely controlled by the combination of vapor–liquid–solid and the vapor–solid mechanism. The photoluminescence spectrum of the ultra-long core–shell SiC/SiO2 nanowires exhibited a significant blue-shift, indicating a potential application in optoelectronic devices.