Kinetic Simulation of Gold Nanorod Growth in Solution Based on Optical Spectra

By monitoring the time evolution of the optical absorption spectrum corresponding to dy-namic information of aspect ratio (AR) and volume, we succeeded in following the growth kinetics of gold nanorods. The results indicate that the rods growth consists of two stages: seeds develop into rods with a fast AR increase and the rods grow big with constant AR. Here, a charge transfer model, involving positive charge transfer from Au(I) to seed and neu-tralization by electron from ascorbic acid, has been introduced to explain the autocatalysis mechanism of rod growth. The good agreement between the numerical simulation based on this moldel and experimental results supports the proposed mechanism.