Construction of MnFe2O4/Bi5O7I composite heterojunction and its visible light–driven photocatalytic degradation of RhB

In order to enhance the photo-induced charge separation efficiency and visible photocatalytic activity, MnFe2O4/Bi5O7I heterojunction composite is constructed and prepared via a simple hydrothermal method, and its photocatalytic degradation performance was evaluated using rhodamine B (RhB) with various composite ratios of MnFe2O4/Bi5O7I. When the composition ratio of MnFe2O4/Bi5O7I reaches 20:100, the degradation efficiency of RhB under visible light irradiation was as high as 84% after adsorption and degradation treatment for 200 min. Furthermore, through the analysis of electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectroscopy, the photocatalytic mechanism with visible light response and photo-induced charge transfer was discussed. All results indicated that the as-prepared MnFe2O4/Bi5O7I heterojunction composite has a potential photocatalytic application in environmental protection field.