摘要
羟胺晶种法制备金纳米粒子时会观察到少量的非球形粒子副产物.研究发现,反应试剂的比例以及试剂的加样顺序对非球形粒子的产生具有明显的影响.羟胺与金氯酸的摩尔比例(NH2OH:HAuCl4)较高时能够抑制非球形粒子的生成,较低时则生成较多的非球形粒子.不同的加样顺序使得加样过程中NH2OH:HAuCl4不同,也可以导致产物中非球形粒子含量的差异.基于以上发现,采用较大的NH2OH用量以维持反应过程中的NH2OH:HAuCl4比例在10～30左右,并采用适当的加样顺序(先将晶种同NH2OH混合,再加HAuCl4),从14nm的晶种出发以逐步(step-by-step)的方式依次合成了平均粒径为26、57、81和130nm的金纳米粒子,产物中基本不含非球形粒子,粒径可控,并具有良好的单分散性(RSD为～10%).
This paper reports a method for the pr eparation of monodispersed gold col loid by seeding growth,with elimination of the nonspherica l by-products,which were often obse rved and difficult to separate in pre vious works.The formation of nonspherica l particles was found to be closely associated with the experimental cond i-tions,such as,molar ratios and addi tion sequence of the reagents.The la rger the[NH 2 OH]:[HAuCl 4 ]ratio,the less and smaller the nonspherical particles.In addition,the effect of a ddition sequence can be ascribed to t hat of [NH 2 OH]:[HAuCl 4 ]ratio,since different addition seq uences make different instantaneous[NH 2 OH]:[HAuCl 4 ]ratios during the addition and thus l ead to different shape distribution of particles.Based on these findings,a method is adopted to rule out the nonspherical particles,by using high ra tios of [NH 2 OH]to[HAuCl 4 ](the[NH 2 OH]:[AuCl 4 ]ratio being kept in the range of 10～30)and favorable addition sequence(NH 2 OH being added to seeds prior to HAuCl 4 ).No nonspherical nanoparticles can be observed,and the resulted gold co lloid shows good monodispersity and excellent size-controllability.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2004年第2期211-215,共5页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(29803002)
科技部973项目(2001CB610501)子课题资助项目~~
