Properties Comparison of Fe3O4 Particles with Different Morphologies as Mimetic Enzyme

In this work, four different magnetic Fe3O4 nanoparticles are prepared via solvothermal method. According to the morphology, the products can be divided into flower-like Fe3O4 (F-Fe3O4), solid spherical Fe3O4 (S-Fe3O4), hollow spherical Fe3O4 (HO-Fe3O4), and hexahedral Fe3O4 (HE-Fe3O4). A set of measurements is performed to confirm the structure, composition, and pore properties of the obtained materials. The catalytic activities of the prepared materials are examined and compared. The results prove that the four materials have an intrinsic catalytic property. HO-Fe3O4 ranks first in the catalytic activity mainly due to its large surface area and reasonable element composition. The maximum specific saturation magnetization and specific surface area of HO-Fe3O4 are 72.94 emu/g and 42.60 m2/g. Fe2+/Fe3+ in HO-Fe3O4 is 51.5%. It is found that HO-Fe3O4 possesses fantastic stability and perfect reproducibility as it is used as a catalyst several times without significant loss in its activity.