Silica nanowires synthesized from gas by-product of SiC synthesis from alkoxide precursors

We synthesised silica nanowires (NWs) without catalysts from the otherwise waste SiO gas by-product of SiC synthesis from alkoxide precursors (phenyltrimethoxysilane and tetraethyl orthosilicate). Separate temperature regions were locally defined in a reactor tube for conversion of alkoxide (1500 °C) and deposition of NWs (1130 °C). Thermodynamic calculations prove that SiO gas abruptly condenses and deposits as silica NWs in the range 1160 to 1000 °C. The factors determining the growth of the NWs in this temperature range were fully elucidated. The photoluminescence spectra revealed differences in oxygen defects in the NWs synthesized under growth conditions with different stability. We expect that this strategy could be extended to synthesize various silica nanostructures from the waste silicon- and oxygen-containing gas by-products of other syntheses.