Novel regrowth mechanism of CdS nanowire in hydrothermal synthesis

Abstract

CdS nanowires were synthesized by a solvothermal method in ethylenediamine solvent, both over a short time (2 h) and a longer time (more than 12 h). The nanowires had an average diameter of ca. 26 nm with a length of ca. 1–3 μm after 200 °C for 2 h, and ∼43 nm average diameter with a length of ∼4–6 μm after 200 °C for 12 h, respectively. These CdS nanowires had a crystalline wurtzite structure, and their crystal growth direction was [0001]. An interesting phenomenon was found where the nanowires synthesized for 2 h broke into nanorods with increasing reaction time. These broken nanorods again grew into nanowires after 12 h. After more than 12 h, the regrowth nanowires became longer and little thicker without other obvious changes. Based on a series of experimental results, it was revealed that the formation of the CdS nanowires followed novel regrowth processes during the hydrothermal synthesis.