Synthesis of gold nanoparticles by pulsed laser-assisted reduction of aqueous gold precursor

摘要

In this paper, colloidal gold nanoparticles (GNPs) were synthesized by Nd:YAG (lambda = 1064 nm) pulsed laser-assisted reduction (PLAR) of aqueous [AuCl4](-). In this process, during laser ablation of a Mo target in DI water, a [AuCl4](-) precursor solution was being added dropwise in situ. UV-Vis absorption spectra showed distinct plasmonic absorption bands at 209 and 530 nm corresponding to Mo nanoparticles (NPs) and GNPs, respectively. Furthermore, no significant conversion for [AuCl4](-) was found when it was added to aged Mo NPs or when it was irradiated in the lack of the Mo target. Using transmission electron microscope (TEM) images, it was found that precursor concentration and laser-ablation time can affect the population or size of GNPs. In PLAR with a small amount of KI solution in water, the GNPs size increases to 50 nm via an iodine-induced particle fusion mechanism. The reduction mechanism was discussed based on metastable species intercation, producing the cavitation bubble during laser ablation.