Synthesis and characterization of Cu, Ag and Au dendrimer-encapsulated nanoparticles and their application in the reduction of 4-nitrophenol to 4-aminophenol.

Here, we report on the synthesis, characterization and catalytic evaluation of Cu, Ag and Au dendrimer encapsulated nanoparticles (DENs). Generations 4-6 of PAMAM-OH and PAMAM-NH(2) were used as templating agents for the synthesis of Cu and Ag-DENs respectively. Generation 4 PAMAM-NH(2) dendrimers were used for the synthesis of Au-DENs. These prepared DENs were characterized using UV visible (UV-vis) spectroscopy as well as a high resolution transmission electron microscopy (HRTEM). The catalytic activity of these DENs was evaluated on the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AMP) by sodium borohydride (NaBH(4)). The reaction was monitored by UV-vis spectroscopy at λ 400 nm. These prepared DENs were found to exhibit good activity for this reduction reaction.