Green synthesis of pd@graphene nanocomposite: catalyst for the selective oxidation of alcohols.

Journal Article

Publication Abstract

Due to their excellent physicochemical properties and synergistic effect, graphene metallic
NPs based nanocomposites have gained significant attention in various technological fields including
catalysis. Here we demonstrate a single pot, facile and environmental friendly synthesis of catalytically
active palladium(Pd)@graphene nanocomposites (SP-HRG-Pd) by the simultaneous reduction of
graphene oxide (GRO) and PdCl2 using Salvadora persica L. (miswak) root extract (RE) as bioreductant.
The synthesis of SP-HRG-Pd was confirmed by various spectroscopic and microscopic techniques,
including ultraviolet–visible (UV–vis), Fourier-transform infrared (FT-IR), Raman and
X-ray photoelectron (XPS) spectroscopy, X-ray powder diffraction (XRD) and transmission electron
microscopy (TEM). The polyphenolic (flavonoids) and terpenoids rich contents of the miswak REnot
only facilitated the reduction of graphene oxide and PdCl2 but also ensured the homogeneous binding
of the Pd NPs on graphene, and through stabilization of the surface of SP-HRG-Pd nanocomposites.
This also led to the enhanced dispersibility of as synthesized nanocomposites in aqueous solutions.
The as-prepared SP-HRG-Pd nanocomposites also demonstrated excellent catalytic activity toward
the selective oxidation of aromatic alcohols. Furthermore, in order to study the effect of calcination
temperature and concentration of Pd NPs on the catalytic activities of nanocomposites, different samples
of SP-HRG-Pd nanocomposites containing different amounts of Pd using various concentrations
of Pd precursor were prepared and calcined at various temperatures.