High-density, ultralong SiO 2 nanotubes were successfully synthesized by a one-step thermal evaporation process using CdSe nanocrystals as the seeds. The as-synthesized products were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, and cathodoluminescence. Varying experimental parameters results in the formation of additional SiO 2 -based nanostructures, such as flowerlike SiO 2 nanotubes and ZnS/SiO 2 core-shell structures. On the basis of these observations, a template-based growth mechanism was proposed for the growth of these nanostructures. Furthermore, the stable and strong visible-light emission properties are of significant interest for their potential applications in future integrated devices.