Facile synthesis of cobalt ferrite submicrospheres with tunable magnetic and electrocatalytic properties

Cobalt ferrite (CoFe2O4) submicrospheres with tunable structures were synthesized by a one-pot solvothermal method through adjusting iron precursors. CoFe2O4 submicrospheres were characterized by a series of technologies including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FTIR), thermal gravity analysis (TGA) and vibrating sample magnetometry (VSM). It was found that single crystal CoFe2O4 submicrospheres were prepared from the synthesis system containing ferric chloride and showed ferromagnetic behavior at room temperature. However, polycrystal CoFe2O4 submicrospheres composed of CoFe2O4 nanocrystals were obtained from ferric nitrate system and displayed superparamagnetic behavior with a magnetization saturation value up to 45.2emu/g. CoFe2O4 spheres obtained from ferric chloride system showed better electrocatalytic performance toward simultaneous determination of dopamine and uric acid than polycrystal CoFe2O4 spheres. The formation mechanisms of CoFe2O4 submicrospheres as well as the structure-property relationship of the spheres were discussed based on the experimental results.