Scalable one-pot synthesis of high-purity silver nanowires via controlled reaction kinetics for transparent conductive ink applications.

Milligram-scale synthesis of nanomaterials needs re-optimization to be translated to gram-scale production. Increasing the reaction volume introduces additional kinetic variables that significantly influence product formation. By systematically addressing these parameters, a simplified protocol based on a modified one-pot polyol synthesis of AgNWs was developed. The method was successfully extended from an optimised small-scale reaction (0.11 g precursor loading/batch) to a 120-fold scale-up (13.2 g precursor loading/batch) without compromising morphology or yield. Notably, the process employs a cost-effective and low-purity precursor (AgNO3, 99.5% purity) instead of the ultra-high-purity precursor (99.9999%) used in the 0.11 g scale reaction while maintaining comparable product quality. The synthesis requires 40-150 min of reaction time depending on the batch size and consistently delivers high isolated yields of 91.0% ± 0.8% with excellent reproducibility. Two well-defined AgNW morphologies were obtained: short nanowires (10-15 µm length and 45 ± 10 nm diameter) and long nanowires (20-42 µm length and 80 ± 10 nm diameter). To demonstrate their practical applicability, the synthesised AgNWs were formulated into conductive inks compatible with non-porous PET substrates. Uniform wire-bar-coated transparent conductive films exhibited an optical transmittance of 88.4% w.r.t PET and an average sheet resistance of 16.23 Ω sq-1, confirming their suitability for applications in solution-processed transparent electrodes and flexible electronic devices.