CoII immobilized on aminated Fe3O4@ cellulose nanofibers (Fe3O4@cellulose nanofibers-NH2-CoII NPs): a novel, bio-based and efficient heterogeneous magnetic nanocatalyst for the synthesis of benzimidazole derivatives

Cobalt immobilized on amine-functionalized magnetic cellulose nanofiber (Fe3O4@CNF-NH2-CoII) was synthesized as a new bio-based nanocatalyst. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy diffraction X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM) and inductively coupled plasma atomic emission spectroscopy (ICP-OES) and its morphology was identified. This magnetic nanocatalyst acted well for efficient synthesis of benzimidazole derivatives through the condensation reaction of aromatic aldehydes and aryl 2,1-diamines by using of ethanol as a solvent under air atmosphere. This nanocatalyst was successfully recycled by an external magnet up to 5 times and reused without a significant decrease in its activity. The use of green solvent, good product efficiency, the use of the recovered nanocatalyst without losing catalytic activity and the simple synthesis method present this method environmentally and economically favorable for synthesis of benzimidazoles.