Crystalline Silver Nanowires by Soft Solution Processing

TLDR

The authors present a soft, solution‑phase method for large‑scale synthesis of uniform bicrystalline silver nanowires with 30–40 nm diameters and lengths up to ~50 µm. The process first generates platinum nanoparticles by reducing PtCl₂ in ethylene glycol at ~160 °C, which then serve as seeds for heterogeneous nucleation of silver reduced from AgNO₃ in the same solvent; surfactants such as PVP guide the growth into nanowires with aspect ratios up to ~1000. Electrical transport measurements at room temperature confirm the nanowires are continuous, exhibiting a conductivity of ~0.8 × 10⁵ S cm⁻¹.

Abstract

This paper describes a soft, solution-phase approach to the large-scale synthesis of uniform nanowires of bicrystalline silver whose lateral dimensions could be controlled in the range of 30−40 nm, and lengths up to ∼50 μm. The first step of this procedure involved the formation of platinum nanoparticles by reducing PtCl2 with ethylene glycol heated to ∼160 °C. Due to their close match in crystal structure and lattice constants, these platinum nanoparticles could serve as seeds for the heterogeneous nucleation and growth of silver that was produced in the solution via the reduction of AgNO3 with ethylene glycol. When surfactants such as poly(vinyl pyrrolidone) (PVP) were present in this solution, the silver could be directed to grow into uniform nanowires with aspect ratios as high as ∼1000. Measurements of transport property at room temperature indicated that these nanowires were electrically continuous with a conductivity of approximately 0.8 × 105 S/cm.