The paper reports on the preparation, characterization, and dispersion of cadmium sulfide (CdS) nanowires using ordered mesoporous silica, SBA-15, as a template. A homogeneous and stable dispersion of hierarchically ordered CdS nanowires in water solubilized with sodium dodecyl sulfate (SDS) has been obtained. Direct imaging of the nanoconnectors (templated by the micropores in SBA-15) between the bundled nanowires has been accomplished by high-resolution transmission electron microscope (HRTEM). Cryogenic-TEM (cryo-TEM) measurements carried out on the dispersed samples complemented by small-angle X-ray (SAX) diffraction and HRTEM examination of the dry CdS powder clarify the role played by the micropores in the formation of a hierarchically ordered array of nanowires in the meso- and atomic scale. The amount of nanoconnectors is controlled by varying the calcination temperature of SBA-15, which tunes the formation of either bundled or individual CdS nanowires. The effect of such organizations is discussed in view of optical absorption and fluorescence measurements.
Dr. T. Rajagopalan and Regev, O., “Hierarchically ordered cadmium sulfide nanowires dispersed in aqueous solution”, Chemistry of Materials, vol. 17, pp. 3281-3287, 2005.