Controlling Length and Monitoring Growth of Gold Nanorods

In this paper, we report a new approach, which could fabricate gold nanowires by controlling the volume of growth solution. The shape evolutions ranging from fusiform nanoparticles to 1‐D rods was observed. Increasing the addition of growth solution can control the length of nanorods. The length of rods can be extended to 2 μm, and nanorods with aspect ratios of up to ˜ 70 could be obtained. Moreover, X‐ray absorption spectroscopy (XAS) is applied herein to elucidate the growth mechanism of gold nanorods. The gold ions were directly reduced to gold atoms by ascorbic acid during the reaction, and then gold atoms were deposited on the surface of gold seeds that were introduced into the reaction. Extended X‐ray absorption fine structure (EXAFS) confirmed the growth of gold and the environment around Au atoms over the reaction. The XAS are expected to have wide applications in the growth of gold and other related materials.