Synthesis of gold nanorods and nanowires by a microwave–polyol method

HAuCl4 was reduced by ethylene glycol, in the presence of polyvinylpyrrolidone (PVP) under microwave (MW) heating in a continuous wave (CW) mode for 2 min. Dominant products were polygonal nanoplates and close-to-spherical nanoparticles of gold. In addition, small amounts of single crystalline gold nanorods and nanowires (0.5–3% of total number of products) with diameters of 20–100 nm and lengths of 0.6–5 μm were produced. The diameter and length of gold nanorods and nanowires could be controlled by changing the HAuCl4·4H2O/PVP ratio. The formation mechanism of anisotropic gold nanostructures was discussed.