Facile synthesis of Pd@graphene nanocomposites with enhanced catalytic activity towards Suzuki coupling reaction

Abstract

A facile and chemical specific method to synthesize highly reduced graphene oxide (HRG) and Pd (HRG@Pd) nanocomposite is presented. The HRG surfaces are tailored with amine groups using 1-aminopyrene (1-AP) as functionalizing molecules. The aromatic rings of 1-AP sit on the basal planes of HRG through π-π interactions, leaving amino groups outwards (similar like self-assembled monolayer on 2D substrates). The amino groups provide the chemically specific binding sites to the Pd nucleation which subsequently grow into nanoparticles. HRG@Pd nanocomposite demonstrated both uniform distribution of Pd nanoparticles on HRG surface as well as excellent physical stability and dispersibility. The surface functionalization was confirmed using, ultraviolet-visible (UV-Vis), Fourier transform infra-red and Raman spectroscopy. The size and distribution of Pd nanoparticles on the HRG and crystallinity were confirmed using high-resolution transmission electron microscopy and powder X-ray diffraction and X-ray photoelectron spectroscopy. The catalytic efficiency of highly reduced graphene oxide-pyrene-palladium nanocomposite (HRG-Py-Pd) is tested towards the Suzuki coupling reactions of various aryl halides. The kinetics of the catalytic reaction (Suzuki coupling) using HRG-Py-Pd nanocomposite was monitored using gas chromatography (GC). The highly reduced graphene oxide (HRG) with its exceptional physicochemical properties is among extensively studied materials in the world 1,2. It is the strongest, thinnest and stiffest material with several remarkable properties, including high thermal and electric conductivities and large theoretical specific surface area 3,4. These unique properties have attracted the vigil eye of researchers in both scientific (academics) and engineering communities (industrial applications) 5. Currently, several methods have been applied to obtain bulk quantities of defect free graphene, which are mainly classified into the bottom-up and top-down approaches 6,7. The most popular methods under the bottom-up approaches include chemical vapor deposition (CVD), chemical conversion, and arc discharge 8,9. Whereas, the top-down approach involve, the sequential oxidation and reduction of graphite. These chemical methods (top-down approaches), offer excellent opportunities for the production of large quantities of graphene like materials, which is best known as highly reduced graphene oxide (HRG) 10,11. The recent advancement in the synthesis of homogeneously dispersed graphene using different reduction and functionalization techniques, have led to the development of various graphene based hybrid materials, such as graphene-inorganic nanoparticles (NPs) based nanocomposites 12,13. The hybridization of inorganic NPs with graphene further enhance the properties and broaden the applications ranging from the medical to the energy

A High‐Performance Asymmetric Supercapacitor Based on Tungsten Oxide Nanoplates and Highly Reduced Graphene Oxide Electrodes

“…The final product, a thick paste, was re‐dispersed in DI water using mild sonication techniques to acquire a graphene oxide (GRO) solution for further processing. GRO was reduced according to our previously reported procedure [61] . Briefly, 100 mg of GRO was dispersed in DI water (30 mL) and sonicated for 30 min.…”

Enhanced Apoptosis by Functionalized Highly Reduced Graphene Oxide and Gold Nanocomposites in MCF-7 Breast Cancer Cells

“…27−29 In our previous study, we have developed a novel approach of employing a hard soft acid base concept to prepare HRG palladium (Pd) nanocomposites (HRG-Pd) using 1-aminopyrene (1-AP) as a stabilizing agent. 30 In this case, 1-AP not only stabilized the surface of HRG through noncovalent π−π interactions but also facilitated the homogeneous nucleation and growth of Pd NPs on the surface of HRG.…”

“…leads to enhanced dispersibility, binding capacity, biocompatibility, and reactivity of the resulting materials . Among various methods, noncovalent functionalization of HRG through π–π interactions using polycyclic aromatic “π–π stacking” molecules, such as pyrene, anthracene, and coronene as stabilizing agents, has gained interest recently. − In our previous study, we have developed a novel approach of employing a hard soft acid base concept to prepare HRG palladium (Pd) nanocomposites (HRG-Pd) using 1-aminopyrene (1-AP) as a stabilizing agent . In this case, 1-AP not only stabilized the surface of HRG through noncovalent π–π interactions but also facilitated the homogeneous nucleation and growth of Pd NPs on the surface of HRG.…”

Electrocatalytic Investigations into a PdNi Nanostructured Alloy Supported over a Graphite Sheet toward Pt-like Hydrogen Evolution Activity

“…X-ray photoelectron spectroscopy (XPS) analysis was further used to determine the composition and chemical structure of the PdNi films deposited for 2 h. The electronic modulation in the PdNi alloy was established by comparing its XPS results with pristine Ni and Pd catalysts. All the peaks were calibrated using C 1s (at 284.60 eV) as a reference for binding energy Figure S3 presents the comparative overview of XPS survey spectra of the as-prepared pristine Ni, Pd, and NiPd alloy.…”