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標題: Aggregate structure and crystallite size of platinum nanoparticles synthesized by ethanol reduction
作者: Wang, S.R.
Tseng, W.J.
關鍵字: Pt nanoparticles
期刊/報告no:: Journal of Nanoparticle Research, Volume 11, Issue 4, Page(s) 947-953.
摘要: Monodispersed platinum (Pt) nanoparticles were synthesized from reducing hydrated hydrogen hexachloroplatinic acid (H(2)PtCl(6)center dot nH(2)O) with ethanol in the presence of polyvinylpyrrolidone (PVP) as a steric stabilizer. Concentration of both PVP and ethanol influenced the aggregate structure and crystallite size of the nanoparticles. When the molar ratio of monomeric unit of PVP to Pt, i.e., [PVP]/[Pt], was one, the synthesized Pt particles coagulated pronouncedly into an inter-connected particulate network or self-organized into spherical superstructures with an apparent diameter ranging from 60 to 80 nm, depending on the ethanol concentration. The geometry and structure of these complex aggregates were characterized by fractal analysis. Fractal dimensions of 2.13-2.23 in three dimensions were determined from the Richardson's plot, which suggests that a reaction-limited cluster-cluster aggregation model (RCLA) was operative. The Pt colloids became apparently more stable when the [PVP]/[Pt] ratio was increased greater than 20. Crystallite size of the Pt nanoparticles was found to increase linearly with the ethanol concentration as the [PVP]/[Pt] was held at one. This suggests that the reduction rate of PtCl(6) (2-) ions in solution is critically important to the synthesized crystallite size.
ISSN: 1388-0764
Appears in Collections:材料科學與工程學系



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