Abstract: Gold nanoparticles with various diameters were synthesized by chemical reduction. UV-Vis spectroscopy and transmission electron microscopy (TEM) were used to characterize the morphology and the size of the prepared Au nanoparticles. The effects of factors, such as the type of the reducing agent, the amount of the reducing reagent, reagent adding order and reaction temperature on the stability, radius, morphology and dispersion of Au nanoparticles were studied. The results show that the size of Au nanoparticles prepared with Na₃C₆H₅O₇ as a reductant was within the range of 15~20 nm, and the size of Au nanoparticles prepared with NaBH₄ as a reducing agent was within the range of 3~10 nm. The optimum molar ratio of Na₃C₆H₅O₇ and HAuCl4 was 1.5:1. The gold nanoparticles prepared after adding HAuCl₄ to the hot mixture of Na₃C₆H₅O₇ and poly vingl pyrrolidone (PVP) solution were better dispersed, smaller in size and more uniform, compared with that prepared after adding Na₃C₆H₅O₇ to the hot mixture of HAuCl₄ and PVP solution.

Key words: preparation of gold nanoparticles, Na₃C₆H₅O₇ reducing agent, NaBH₄ reducing agent, poly vingl pyrrolidone (PVP), transmission electron microscopy (TEM)

摘要： 通过化学还原法制备出不同粒径的纳米金颗粒。利用紫外可见分光光度计和透射电子显微镜对纳米金颗粒的形貌及尺寸进行表征。讨论了还原剂种类、还原剂用量、试剂加入顺序、反应温度等因素对纳米金颗粒稳定性、粒径、形貌和分散性的影响。结果表明: Na₃C₆H₅O₇为还原剂制得纳米金颗粒粒径在15~20 nm之间, NaBH₄为还原剂制得的纳米金颗粒粒径在3~10nm之间, 柠檬酸钠与氯金酸的摩尔比为1.5:1时最佳, Na₃C₆H₅O₇为还原剂时, 采用NaBH₄溶液加入到加热的Na₃C₆H₅O₇与聚乙烯吡咯烷酮(PVP)混合溶液比Na₃C₆H₅O₇溶液加入到加热的NaBH₄与PVP混合溶液制得的纳米金溶胶的颗粒分散性好, 粒径小且更均一。

关键词: 纳米金制备, 柠檬酸钠还原剂, 硼氢化钠还原剂, 聚乙烯吡咯烷酮(PVP), 透射电子显微镜