▎ 摘　　要

Magnetic graphene oxide (GO)/amino-functionalized Fe3O4 nanocomposite was prepared using tannic acid as binder. For this purpose, Fe3O4 nanoparticles were modified by phenylenediamine and GO was partially reduced and modified in presence of tannic acid. Nanocomposites were prepared under three different synthesis conditions. The morphology and chemical structure of the magnetic GO nanocomposites were studied by means of Fourier-transform infrared spectroscopy, X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating-sample magnetometry. The catalytic activity of the optimal GO/Fe3O4 nanocomposite was then studied using reduction of 2,4-dichloro-6-methyl-5-nitropyrimidine at different catalyst doses. The reaction time was probed using ultraviolet-visible (UV-Vis) absorption spectroscopy and thin-layer chromatography (TLC) analysis. The results demonstrated that, on increasing the catalyst dose from 1 to 7mg, the reaction time decreased from 20 to 5min. The synthesized product was also confirmed by nuclear magnetic resonance. The very low catalyst dose required, green media, and low temperature demonstrate that the as-prepared magnetic GO catalyst has high catalytic activity for reduction of nitropyrimidine to aminopyrimidine in aqueous medium.