Anisotropic Growth of Copper Nanorods Mediated by Cl^- Ions

Anisotropic growth to form Cu particles of rod and wire shapes has been obtained typically in a complex system that involves both organic capping agents and Cl^- ions. However, the sole effect of Cl^- ions on the formation of Cu wires has yet to be fully understood, especially in an organic system. This present work determines the effect of Cl^- ions on the morphologies of Cu particles in an organic phase without any capping agents. The results revealed that anisotropic Cu rods could be grown with the sole presence of Cl^- ions. The rods have the (011) facets as the long axis, the (111) facets as the tip, and the (100) facets as the side surface. By increasing the Cl^- ion concentration, more Cu atoms contributed to the formation of Cu rods and the kinetic growth of the length and the diameter of the rods varied. This suggests that Cl^- ions have preferential adsorption on the (100) Cu surfaces to promote the anisotropic growth of Cu. Meanwhile, the adsorption of Cl^- to the (111) and (100) surfaces at high Cl^- concentrations regulates the relative growth of the particle length and diameter.