Synthesis heterogeneous and recyclable magnetic nanocatalysts by decorated amino-modified multi-walled carbon nanotubes with iron and silver nanoparticles (MWCNTs-NH2/Fe3O4/Ag NPs) for organic dyes reduction

The present study described a novel magnetic nanocatalyst by iron oxide and silver nanoparticles decorated over amino-modified multi-walled carbon nanotubes (MWCNTs-NH2/Fe3O4/Ag NPs) for organic dye reduction. Scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Vibratingsample magnetometer (VSM) and UV-Vis spectroscopy were used to characterization of desired catalyst. It was concluded that MWCNTs-NH2/Fe3O4/Ag NPs is efficient nanocatalyst that can reduce different organic dyes, such as 4-nitrophenol (4-NP), methyl orange (MO) and Methylene blue (MB) in the attendance of NaBH4 at room temperature. Using UV-Vis spectroscopy over time, the reaction solution was studied. The ln (Ct/C0) values of all colors were changed linearly with time, which demonstrated that 4-NP, MB and MO reduction in the presence of the MWCNTs-NH2/Fe3O4/Ag NPs as nanocatalyst and more NaBH4 followed pseudo-first-order kinetics. Then finally, the synthesized catalyst was collected from the reaction medium by an external magnet and reused 8 times without losing its catalytic activity.