Synthesis and characterization of a magnetic nanocatalyst base on graphene oxide, Nickel and Cobalt and its activity in organic reactions

Today catalysts are widely used in the production of various materials. Nano-catalysts according to their importance have become one of the most important areas for nanotechnology research.1 Development of magnetic catalysts for carbon-carbon and carbonheteroatom coupling reactions are one of the most important issues in terms of applications to organic synthesis.2 At present, many researches are focused on the construction of more active and more stable, heterogeneous Nano-sized metal catalysts, which can be recovered and reused.3 Nickel and cobalt nanoparticles due to low prices, magnetic properties, and high chemical activity attracted particular attention.2 In this work, nickel and cobalt nanoparticles were synthesized with a green and one-pot method on graphene oxide substrate for reduction reactions of 4-nitrophenol and Heck, Suzuky, Negishi, and Sonogashira cross-coupling reactions. Several characterization techniques such as FTIR, FESEM, XRD, and VSM were employed to characterize the Co and Ni nanoparticle reduced graphene oxide composites witch indicates that nickel and cobalt magnetic particles with a size of about 20-30 nanometers were uniformly anchored on graphene oxide nanosheets. In addition, results showed that incorporation of Co and Ni nanoparticles and GO produce much higher activity in cross-coupling and reduction reactions. The soft-ferromagnetic behavior of the RGO/CoxNi100-x nanocomposite demonstrated the easy separable from the reaction mixture and reusable several times without losing its catalytic activity, Hence, the RGO/CoxNi100-x composites can be a potential promising material to catalyze the cross-coupling reactions.

Keywords:

Ni , Co , Graphene oxide , Nanocatalyst , Cross-coupling reactions.