Nanostructures and Optical Properties of Mesoporous Composite Nanofibers Containing CdS Quantum Dots

Abstract

Mesoporous silica nanofibers containing CdS quantum dots (QDs) were fabricated by the confined self-assembly of a lyotropic mesophase within the nanochannels of porous alumina. The resulting mesoporous nanofibers show unique internal mesostructures that depend on the size of the incorporated CdS QDs. Porous nanochannels of the composite nanofibers are shown to form a circularly wound assembly perpendicular to the long fiber axis with small QDs incorporated. As the diameter of the CdS QDs within the silica nanofibers increases, the circularly wound nanochannels become disordered. This unique mesoporous structure is further perturbed by increasing the amount of incorporated CdS QDs. The perturbed mesostructure inside the nanofibers results in an enhanced efficiency of nitrogen gas adsorption and spectral changes of the incorporated QD emissions. Such perturbed nanochannels inside the nanofibers can be utilized as a preferred mesostructure for adsorbing gas molecules and removing surface emission states of the CdS QDs.