Solvothermal synthesis of cobalt ferrite hollow spheres with chitosan.

Cobalt ferrite hollow spheres with chitosan (CoFe2O4/CS) were synthesized by two different approaches using the solvothermal method. The first approach involves in-situ incorporation of FeCl3:6H2O and CoNO3:6H2O in the solvothermal reaction (M1) and in second approach already prepared CoFe2O4 nanoparticles (NPs) using the thermal decomposition method was placed in the solvothermal reaction to form the hollow spheres (M2). Structural identification of the samples were characterized by Fourier transform infrared spectra (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analyses (DSC-TGA) and energy dispersive X-ray spectroscopy (EDX). The magnetic properties were evaluated using a vibrating sample magnetometer (VSM). The presence of chitosan on the hollow sphere was confirmed by FTIR. The XRD analyses proved that the synthesized samples were cobalt ferrite with spinel structure. The structure of the surface and the average particle size of the spheres were observed by SEM and TEM showing the nano scale of the CoFe2O4 component. Structural characterization demonstrating that chitosan does not affect the crystallinity, chemical composition, and magnetic properties of the CoFe2O4/CS. This work demonstrates that the CoFe2O4/CS prepared using the as synthesized CoFe2O4 NPs have better structural and magnetic properties.