Preparation of magnetic Fe_3O_4 nanoparticles by microbial reduction combining natural oxidation method

摘要

By using microbial reduction combining natural oxidation method, magnetic Fe_3O_4 nanoparticles have been synthesized. Sulfate-reducing bacterium(SRB) was used to reduce ferric sulfate to produce ferric sulfide, then ferric sulfide was oxidized to iron protoxide and ferroferric oxide in the end under natural air oxidation condition. The size and morphology of the product and SRB was examined by scanning electron microscopy(SEM), the microstructure were investigated by X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS). There are only two components (xFeO and yFe_3O_4)which is testified by XRD and EDS. The constituents of product were analysed by using energy dispersive spectroscopy(EDS). In result, x, y actual numerical value which is respectively mole fraction of FeO and Fe_3O_4 in the product is figured out 0.678 and 0.322.