Template fabrication of SiO₂ nanotubes

The authors report the preparation of silica nanotubes by a simple two-stage thermal evaporation of ZnSe and SiO powders. Firstly, nanocables with single crystalline ZnSe nanowire cores and amorphous Si O2 shells were formed by a combined vapor-liquid-solid and SiO-assisted growth process. The ZnSe cores were then evaporated at high temperatures leaving behind Si O2 nanotubes. As-fabricated Si O2 nanotubes were studied with scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopic analysis, and photoluminescence measurement. The Si O2 nanotubes were found to be amorphous, diameter uniform, smooth, and rigid. This method can be used to prepare other materials and morphology-controlled nanotubes.