Large-scale preparation of Fe@Fe2O3 nanoscale stirring bars with ultrahigh saturation magnetization

摘要

The core@shell structured Fe@Fe2O3 nanoscale stirring bars (denoted as Fe@Fe2O3 NSBs) were facilely synthesized through the injection of ferric chloride solution into sodium borohydride solution at mild condition in one pot. The Fe@Fe2O3 NSBs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometer. Results showed that the Fe@Fe2O3 NSBs owned lengths of several micrometers, diameters of 40-60 nm, and ultrahigh saturation magnetization of 130.1 emu/g at room temperature, exhibiting high magnetic response to the external rotating magnetic field. More interestingly, the Fe@Fe2O3 NSBs display excellent peroxidase enzyme-mimicking activity for the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). Meanwhile, in microscopic catalytic systems, the Fe@Fe2O3 NSBs have been proved to accelerate mass transfer for the hydrogenation of methylene blue. (C) 2017 Elsevier B.V. All rights reserved.