Novel Fabrication of Silver-Coated Copper Nanowires with Organic Compound Solution

Copper nanowires and Cu-Ag nanowires have various potential applications, such as transparent conductive film, flexible electronics, and conductive filler. In this study, we developed a new green fabrication method for silver-coated copper nanowires using methylsulfonylmethane (DMSO2), which is an environmentally friendly chemical at the food-grade level, to replace toxic chemicals, including ammonia, in the silver coating process. Copper nanowires were synthesized under various reaction temperatures and concentrations of hydrazine (N2H4), ethylenediamine (EDA), sodium hydroxide (NaOH), and copper precursor. The reaction temperature higher than 70 degrees C caused the oxidation of copper products and evaporation of the sample solution. The optimal conditions to synthesize copper nanowires more than 18 mu m in length and 25-45 nm in diameter were determined: 9 M of NaOH, 50 mu L of EDA, 17 mM of CuCl2, 5.7 mM of N2H4, and 70 degrees C reaction temperature. Cu-Ag nanowires, which have about a 12 nm thick silver shell, were successfully fabricated at room temperature under 1 mM of silver nitrate (AgNO3) and 1 wt % of DMSO2. Synthesis conditions for copper and silver-coated copper nanowires have been optimized.

Automated summary

In this study, a green fabrication method using methylsulfonylmethane was developed to synthesize silver-coated copper nanowires, replacing toxic chemicals in the process. The optimal conditions for synthesizing copper nanowires and Cu-Ag nanowires were determined through optimization.