Oxo-vanadium complex immobilized on chitosan coated-magnetic nanoparticles (Fe3O4): A heterogeneous and recyclable nanocatalyst for the chemoselective oxidation of sulfides to sulfoxides with H2O2

Abstract

This article presents the synthesis of Schiff base oxo-vanadium complex immobilized on chitosan coated-magnetic Fe3O4 nanoparticles [VO(CS)@Fe3O4] as a new magnetic interphase nanocatalyst. This type of functionalizing the surface of magnetic particles is a graceful method for bridging the gap between two types of heterogeneous and homogeneous catalysis. The characterization of as-synthesized nanocatalyst was performed through Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). The chemoselective oxidation of sulfides to sulfoxides using green oxidant of hydrogen peroxide at ambient temperature in high-yield was catalyzed with VO(CS)@Fe3O4. The synthesized catalyst can be used up to 8 times with no considerable leaching and change in its activity. Both improvement of catalytic performance and easy separation for the reaction procedure were obtained because of the presence of oxo-vanadium and the magnetic core.