Fabrication of Nitrogen-enriched Graphene Oxide/Cu NPs as a Highly Efficient and Recyclable Heterogeneous Nanocatalyst for the Chan-Lam Cross-Coupling Reaction

Herein, we demonstrated the direct polymerization of melamine and cyanuric chloride in thesurface of graphene oxide (GO) (N-enriched GO) for the development of new nanocatalyst.The supramolecular polymerization of GO not only as a spacer to prevent the restacking ofgraphene sheets but also as a nitrogen source to generate active centers for Cu NPsattachments. Subsequently, the nitrogen decorated on the surface of the graphene oxide sheetscoordinated with copper ions to generate copper nanoparticles (Cu NPs). The prepared nanocatalystwas characterized by Fourier transform infrared (FT-IR), X-ray powder diffraction(XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX),thermogravimetric analysis (TGA) and atomic force microscopy (AFM). This catalyst showedhigh efficiency and good activity in Chan-Lam cross-coupling reaction of N-heterocycles, aliphaticamines and aniline derivatives with high yields in short reaction times. In addition,nanocatalyst was easily recovered and reused for five consecutive runs without noticeable lossof performance.