Graphene oxide (GO) and transition metal complexes are two well-studied systems owing to their diverse applications and superior properties. Herein, GO/Fe3O4 nanostructure was prepared and used as a support for grafting Schiff base-Cu complex. This novel nanocatalyst was synthesized through modification of GO using Schiff base-Cu complex [GO/Fe3O4/Schiff base-Cu] being an eco-friendly, convenient and cost-effective procedure. The product was studied by various characterization techniques whose results revealed that the copper complex was grafted on the surface of the magnetic graphene oxide. The obtained nanocomposite shows chemical and thermal stabilities, as well as significant catalytic behavior. GO/Fe3O4/Schiff base-Cu nanocomposite was investigated as an efficient catalyst in the reduction of 4-nitrophenol and dyes, including methylene blue (MB) and Congo red (CR) with sodium borohydride in room temperature and aqueous solution by checking the reaction progress via visible–ultraviolent spectroscopy. Also, the catalytic activity of the novel nanocatalyst was evaluated in Knoevenagel condensation and Michael-type addition for the preparation of 2-amino 4H-chromene in ethanol/water green solvent at the temperature of 60 °C. The results showed that the synthesized nanocatalyst isolated magnetically can be reused for 4 times with no remarkable loss in the product yield. The synthesis method employed here demonstrated mainly the advantages of being ecofriendly and simple, excellent yields and high efficiency, usage of non-toxic solvent, as well as easiness of product isolation using ethanol.
