Facile one-pot synthesis of crystalline palladium nanoparticles with exceptional catalytic and antiradical activities

It is for the first time that the essential oils of medicinal plants are used for the synthesis of palladium nanoparticles, one of the rarest and precious transition metals known to mankind. In the present study, leaf essential oil of Coleus aromaticus and Myristica fragrans is used as the bioreductant. The appearance of an absorption continuum in the UV-vis spectrum indicates the formation of palladium nanoparticles. The effect of varying quantities of biomaterial on the synthesis of nanopalladium is studied. TEM micrographs disclose the formation of clusters of well dispersed nanospheroids of size similar to 2.8 nm. Sharp peaks in the XRD are indexed to Bragg reflections from planes corresponding to face centred cubic crystalline structure. FTIR spectral analyses reveal the participation of terpenoids and phenolic ether derivatives in reduction and capping. The synthesized nanoparticles exhibit significantly high catalytic efficiency in degrading a broad spectrum of organic pollutants including methyl red, methyl orange, eriochrome black T, methylene blue, rhodamine B, ortho-, meta- and para-nitrophenols. The reduction reactions are observed to obey pseudo first order kinetics. Antioxidant potential of the as synthesized palladium nanoparticles is portrayed through DPPH assay, nitric oxide and hydroxyl radical scavenging activities and reducing power activity. (C) 2015 Elsevier B.V. All rights reserved.