Rhodium nanoparticles supported on 2-(aminomethyl)phenols-modified Fe3O4 spheres as a magnetically recoverable catalyst for reduction of nitroarenes and the degradation of dyes in water

A magnetic nanostructured catalyst (Fe 3 O 4 @SiO 2 -Amp-Rh) modified with 2-(aminomethyl)phenols (Amp) was designed and prepared, which is used to catalyze the reduction of aromatic nitro compounds into corresponding amines and the degradation of dyes. The 2-aminomethylphenol motif plays a vital role in the immobilization of rhodium nanoparticles to offer extraordinary stability, which has been characterized by using various techniques, including transmission electron microscopy (TEM), thermal gravimetric analyzer (TGA), X-Ray Diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). A variety of nitroaromatic derivatives have been reduced to the corresponding anilines in water with up to yields of 99% within 1 h at room temperature. In addition, the catalyst system is effective in catalyzing the reduction of toxic pollutant 4-nitrophenol and the degradation of MO, MB and RhB dyes. Importantly, this catalyst Fe 3 O 4 @SiO 2 -Amp-Rh can be easily recovered by an external magnetic field because of the presence of magnetic core of Fe 3 O 4 , and the activity of Fe 3 O 4 @SiO 2 -Amp-Rh does not decrease significantly after 7 times’ recycling, which indicates that the catalyst performed high reactivity as well as stability. Graphical abstract