Construction of novel 3D ZnO hierarchical structure with Fe₃O₄ assist and its enhanced visible light photocatalytic performance

In order to improve the visible light photocatalytic ability of ZnO semiconductor, a novel 3D Fe₃O₄/ZnO hierarchical structure (defined as 3D F-ZnO) has been successfully constructed by a Fe₃O₄ nanosphere assisted hydrothermal method. The forming mechanism was proposed. Its morphology, crystal structure, and visible light response property were studied via SEM, XRD, and DRS. The diameter of 3D F-ZnO was about ∼4.5âμm and it was assembled by numerous of asymmetric cone-shaped ZnO nanorods on a Fe₃O₄ nanosphere. 3D F-ZnO structure exhibited good optical response property and enhanced visible light photodegradation ability toward Cong red (84 %). 3D F-ZnO also displays good ability on the degradation of tetracycline (90 %) and methylene blue (60 %) under visible light irradiation. Influence of heavy ions, acid groups, water sources on degradation CR was investigated to further confirm the pratical applicability of 3D F-ZnO structures. The 3D F-ZnO can be recycled by the magnet. The primary reactive species of ·OH, ·O₂^-, and h⁺ were confirmed in the photodegradation process. The 3D F-ZnO hierarchical structure may have great potential in water treatment and other photocatalytic fields.