Guoan Du

In situ micelle–template–interface reaction route to CdS nanotubes and nanowires

CdS nanotubes and nanowires have been successfully synthesized via an in situ micelle–template–interface reaction (ISMTIR) route by adjusting the concentration of the surfactant. The whole reaction system is made up of SDS rod-like micelles as the template, CS2 as the oil phase and sulfur source, NH3 as the attacking agent and coordination-agent, and CdCl2 in water. It was found that SDS rod-like micelles were excellent templates for the growth of nanotubes and nanowires of small size. Due to a micelle diameter of 10–20 nm, the CdS nanotubes formed have an outer diameter of 15 nm on average and a wall thickness of ca. 5 nm, within the exciton diameter of bulk CdS. In particular, the formation of CdS nanowires was thought to occur by a “rolling-broken-growth” (RBG) process, in which the micelles could not support the strain of the CdS produced rolling. Thus, the diameter of as-obtained CdS nanowires was ca. 5 nm, within the exciton diameter, too. The UV-vis absorption spectra show the as-obtained CdS nanotubes and nanowires are well quantum-confined. In the future, this method is expected to be used to prepare other metal sulfide nanotubes and nanowires.

A solvent-reduction and surface-modification technique to morphology control of tetragonal In2S3 nanocrystals

In2S3 nanoparticles, short nanowhiskers, nanorods and finger-structure nanocrystals with stoichimetric composition and high quality can be prepared by a solvent-reduction route. It was found that the reagent concentrations, solvent and reaction temperature played important roles in the shape control. We also successfully used CTAB to modify the shape of products. The resulting structures were found to be quantum-confined.