Synthesis of Rhombic Dodecahedral Fe3O4 Single Crystals Towards Their High Peroxidase-Like Activity

摘要

A solvothermal method has been developed to synthesize rhombic dodecahedral (RD) Fe3O4 single crystal structures bound by high-energy active {110} facets from inorganic Fe salts and N2H4 in N, N-dimethylformamide solution. The growth process and formation mechanism of the RD Fe3O4 structures was investigated in detail by changing different parameters. The as-synthesized products exhibit high magnetic properties with saturation magnetization value of 80 emu/g and coercive force value of 57 Oe. The RD Fe3O4 structures possessing active basal facets showed excellent peroxidase-like catalytic activity towards oxidation of methylene blue (MB) dye in the presence of H2O2. After deposition of Au nanoparticles on the RD Fe3O4 structures, the Fe3O4/Au composites exhibit enhanced catalytic activity towards MB in the absence of H2O2. The Fe3O4 and Fe3O4/Au composites can be easily recycled from the treated water using a magnet. There was no obvious decrease of the peroxidase-like catalytic activity of the RD Fe3O4 structures after being used even for six cycles.