Preparation of Dendrimer-like Gold Nanoparticles by Electrochemical Method

摘要

It is well known that gold nanoparticle is the most important noble metal material for wide applications due to its unique optical responses, catalysis, photography, biosensing and electronic properties. Among the applications, performance and characteristics are strongly dependent on the size, shape, composition, morphology, and impurities of the gold nanoparticles. Thus, effectively controlling the nanoparticle shape and size is of high importance and is a challenging task for researchers and the industry. Recently, novel and interesting shapes of gold nanoparticles have been studied. They include nanorings, nanoplates, nanorods, nanowires, nanoprisms, spheroids, dogbone-like, and nanonetworks (1-8). The development of the well controlled shapes and novel structures of gold nanoparticles have therefore become an emerging research topic. Previously, we have developed a simple electrochemical method for the fabrication of gold nanoparticles in various shapes, such as spheres, crooked nanocrystals, networked structures, nanocubes, and nanodumbbell (9-16). As for the electrochemical procedure in obtaining gold nanoparticles, the bulk gold at the anode is oxidized to form gold cations, which then migrate to the cathode. The reduction reaction at the cathode successively occurs with the formation of gold ad-atoms on its surface during the electrolysis. The gold ad-atoms in the growth solution are then trapped by the surfactant to form the nanoparticles. Generally, in the fabrication of these special-shaped nanoparticles, a template method with a dynamic surfactant micelle system, is considered to be highly suitable. The addition of a small amount of organic solvent to surfactant solution is necessary for the enhancement of the formation of various micelle shapes.In this work, we will report the fabrication of dendrimer-like gold nanoparticles (DGNs) through the electrochemical method. It is determined that the addition of a