Synergetic effect of ultrasound and sodium dodecyl sulphate in the formation of CdS nanostructures in aqueous solution

High aspect ratio (>1000) CdS nanostructures were prepared via ultrasound treatment of parent nanowires (NWs) dispersed in sodium dodecyl sulfate (SDS) aqueous solution. The CdS parent NWs were prepared using ordered mesoporous silica, SBA-15, as a template. The elongated nanostructures (ENS), namely, NWs, nanoribbons and nanotubes, form stable dispersions in aqueous solutions. Electron microscopy and X-ray diffraction techniques were used to characterize both the parent NWs and the ENS. While the structure of the parent NWs is crystalline cubic, the ENS are amorphous. We show that the amorphous ENS bud from the parent bundled NWs. Ultrasound power and duration, presence of commensurate surfactant and calcination temperature of the templating SBA-15 are critical parameters in the formation of ENS in aqueous solution.