Preparation of PAMAM− and PPI−Metal (Silver, Platinum, and Palladium) Nanocomposites and Their Catalytic Activities for Reduction of 4-Nitrophenol

摘要: Dendrimer-metal (silver, platinum, and palladium) nanocomposites are prepared in aqueous solutions containing poly(amidoamine) (PAMAM) dendrimers with surface amino groups (generations 3, 4, 5) or poly(propyleneimine) (PPI) 2, 4). The particle sizes of the metal nanoparticles obtained almost independent generation as well concentration dendrimer for both PAMAM PPI dendrimers; average silver, palladium 5.6-7.5, 1.2-1.6, 1.6-2.0 nm, respectively. It is suggested that dendrimer-metal formed by adsorbing on nanoparticles. Studies reduction reaction 4-nitrophenol these show rate constants very similar between dendrimer-silver nanocomposites, whereas dendrimer-platinum -palladium greater than those corresponding nanocomposites. In addition, it found involving all decrease an increase concentrations, catalytic activity dendrimer-palladium highest.