Facile fabrication of ZnO nanorods modified Fe_3O_4 nanoparticles with enhanced magnetic, photoelectrochemical and photocatalytic properties

摘要

Novel Fe3O4/ZnO magnetic nanocomposites with a hierarchical morphology were synthesized by a facile two-step liquid chemical method. The structure, morphology, chemical composition, magnetic behavior and optical property of the samples were examined. The as-prepared nanocomposites were composed of discoid-like and chip-like Fe3O4 nanoparticles coated by ZnO nanorods. Meanwhile, the amount of Fe3O4 precursor in composite had significant influence on the microstructure and optical property. The unique Fe3O4/ZnO-2 showed a relatively large specific surface area with 168.01 m(2).g(-1), hierarchical porosity and enhanced optical response. In magnetic measurement, Fe3O4/ZnO-2 had an excellent superparamagnetic property with 44.77 emu/g of saturation magnetization. Furthermore, the magnetic nanocomposite possessed a higher adsorption capacity to Rhodamine B (RhB) dyes compared with bare ZnO, which would contribute to its use for photocatalytic degradation. For the photocatalytic degradation of RhB, the Fe3O4/ZnO-2 sample showed the highest photocatalytic efficiency (76.46%) under a low-power UV light, compared to that of 71.13% by bare ZnO. In addition, the Fe3O4/ZnO photocatalyst provided more efficient magnetic separation and better photoelectrochemical property than individual oxide. The favorable photocatalytic activity can be attributed to synergistic effect of unique microstructure, large surface area, and strong light absorption.