Single-step in situ seed-mediated biogenic synthesis of Au, Pd and Au-Pd nanoparicles by etlingera elatior leaf extract

Abstract

The rapid formation of stable Au-Pd bimetallic nanospheres are based on a single-step, seed-mediated, growth method using Etlingera elatior leaf extract as a reducing, stabilizing and capping agent. The success of this synthesis is attributed to reduction potential difference of Au and Pd, where Pd initially form seeds in the reaction mixture, followed by growth of Au around the Pd seeds forming Au-Pd bimetallic nanoparticles. Consequently, monometallic Au nanoparticles with mixtures of shapes can be well controlled. The used of Etlingera elatior as a reducing agent is a simple one-pot environmentally friendly reaction, non-toxic and safe method without the need of additional surfactant, capping or stabilizing agent. The synthesized Au-Pd, Au and Pd nanoparticles were characterized via UV-vis, FTIR, XRD, CV, TEM and EDX analysis. TEM analysis revealed that Au-Pd nanoparticles consisted of only nanospheres with mean size of 17.8 ± 9.9 nm, as opposed to the Au nanoparticles that have mixtures of anisotropic nanoshapes with mean size of 15.8 ± 6 nm. FTIR spectroscopic analysis of the biosynthesized Au, Pd and Au-Pd nanoparticles confirmed the surface adsorption of the bioactive components in the leaf extract that acted as the reducing agent and stabilizer for the metal nanoparticles.