Electrochemical Investigation on the Formation of Cu Nanowires by Electroless Deposition

The growth of copper (Cu) nanowires by electroless deposition in aqueous solution at 60-80 degrees C was studied from an electrochemical perspective using in situ mixed potential measurements and potential-pH diagrams. Scanning Electron Microscopy (SEM) showed that thick and short nanowires were obtained at high temperatures, while long and thin nanowires result from low reaction temperatures. In situ mixed potential measurements reveal that Cu(II) reduction is more favored at higher reaction temperatures, hastening the reduction reaction. The fast reaction leads to a high concentration of Cu atoms in the solution. As a result, Cu deposition occurs rapidly, such that they attached on both sides and ends of the primary Cu nanowires. This results to the formation of thick and short structures. On the other hand, thin and long nanowires are obtained due to the slow reduction reaction, which gives the Cu atoms more time to orderly attach in a wire-like formation.