Impact of microwave power on the preparation of silver nanowires via a microwave-assisted method

Abstract

The microwave-assisted method is rapid in synthesizing silver nanowires. However, a by-product of silver particles is often simultaneously produced. For better utilization of microwaves to produce silver nanowires, the effect of microwave power on the morphologies of silver nanostructures was studied. The synthesis was conducted at various single microwave powers, 80, 160, 320, 560 and 800 W and with a combination of 800 W and 320 W with different sequences and time assignments. The results showed that 320 W produced silver nanowires of 6–8 μm, while when a lower power was used, silver nanowires were shortened to 2–4 μm. At higher microwave power, vast silver particles dominated the product with short nanowires of about 3–4 μm. In addition, the combination of 800 W × 0.5 min + 320 W × 2.5 min ideally resulted in mainly uniform silver nanowires up to 10 μm in length, with a small quantity of silver particles. However, prolonged treatment at 800 W during the first heating phase and the reversed combination of 320 W + 800 W led to a high yield of silver particles. We believe that different microwave powers lead to products of various morphologies by impacting on the reduction rate and seed growth. Generally, this study highlights the microwave power dependent effects on silver nanostructures and a better utilization of microwave power combination to synthesize silver nanowires.