Efficient synthesis of ultra-long, high-yield Ag nanowires via supersaturation modulation for transparent conductors

High-quality silver nanowires (Ag NWs) are essential for the next-generation flexible transparent conductors (TCs). However, current synthesis methods predominantly rely on inefficient empirical trial-and-error approaches, lacking a universal theoretical framework. Here, we employ the results of thermodynamic analysis to precisely control the in-situ formation of ideal Ag nuclei with tailored crystalline phases and exposed surfaces via supersaturation modulation, enabling the efficient synthesis of high-quality Ag NWs. We found that the addition of two-dimensional additives, such as graphitic carbon nitride (g-C₃N₄), MoS₂, WS₂, Ti₃C₂Tₓ, and graphene oxide (GO), effectively reduces the supersaturation of the crystal growth units, thereby suppressing random nucleation and favoring the formation of high-purity penta-twinned seeds with low-surface-energy (111) facets. Such control over nuclei allows the production of Ag NWs with an average length of 227 μm (aspect ratio > 2200) at a yield of 93%. Consequently, the resulting TCs exhibit a transmittance (T) of 87% at 550 nm and a sheet resistance (R_sq) of 5 Ω/sq, outperforming conventional indium tin oxide (ITO) (typically, T = 84% at 550 nm, R_sq = 10 Ω/sq). Furthermore, when used as transparent heaters, they can reach approximately 118 °C with a rapid heating rate of 10.5 °C/s at a low voltage of just 5 V. This study innovatively proposes a universal mechanism for synthesizing high-quality Ag NWs, facilitating their diverse applications.