Synthesis and characterization of Cu-Ni and Cu-Co nanowires obtained using CTAB as surfactant

This work reports the tuned chemical synthesis of copper-based nanowires, including metal nanostructures of pure Cu, Cu–Ni, and Cu–Co. The synthesized nanostructures were evaluated by scanning electron microscopy (SEM), energy dispersive analysis (EDX), and X-ray diffraction (XRD). The results confirmed the synthesis of metallic copper nanowires using ODA (octadecylamine) as surfactant, and glucose as reducing agent, through a hydrothermal method. These nanostructures were then used as metal core for the synthesis of bimetallic nanowires. Thus, two different surfactants, polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB), were used for the synthesis of Cu–Ni core–shell nanowires, using hydrazine as reducing agent, in order to explore the effect of CTAB on this synthesis. Interestingly, PVP promoted higher crystallinity, in agreement with earlier studies, while CTAB led to more efficient nickel deposition on the core nanowires. Finally, CTAB was used for the new synthesis of bimetallic Cu-Co nanowires. These results confirm a key advance about using a new surfactant (CTAB) for synthesizing bimetallic nanowires, finding a new method for obtaining Cu–Co nanowires without needing external magnetic fields (a typical condition reported currently in the literature). The findings open a promising pathway for fabricating complex bimetallic nanostructures through straightforward chemical methods.