CdS Nanowires with Large Aspect Ratio and Their Composite with CuS and Au Nanoparticles

We prepared CdS nanowires with small diameter (2.9 nm) and a large aspect ratio (more than 60) via a seed growth method. Wurtzite CdS seeds were firstly obtained via an organic synthesis at 310 degrees C. CdS nanowires with a single-crystal wurtzite structure and grown along the [0001] (c-axis) were further created through controlling the growth process. The injection of precursors plays an important role for getting a large respect ratio. The average size of the seeds is 2.9 nm. The growth along c-axis occurred during the preparation of the nanowires. The diameter of 2.9 nm remained unchanged within short reaction time. The heterostructures of the nanowires were fabricated by depositing CuS and Au nanoparticles (NPs). CuS monomers firstly deposited on the top of the nanowire and then to form a CuS shell on the top. In contrast, Au NPs deposited firstly on the top part of the nanowire. With increasing time or the amount of precursors, small Au NPs on side part of the nanowire was observed. The possible deposition kinetics was discussed. Because of homogeneous and uniform morphology, the heterostructures may be utilizable for applications.