Highly efficient visible-light-driven photocatalytic degradation of rhodamine B by a novel Z-scheme Ag3PO4/MIL-101/NiFe2O4 composite

Abstract

The effectiveness of metal–organic frameworks (MOFs) as solid-state electron mediators for rhodamine B (RhB) degradation in a Z-scheme photocatalysis system is demonstrated. Novel Z-scheme Ag₃PO₄/MIL-101/NiFe₂O₄ (APO/MOF/NFO) composites were synthesized by an in situ precipitation method and employed to degrade RhB dye under visible-light irradiation. The photocatalytic activity results demonstrated that the Z-scheme APO/MOF/NFO(20%) photocatalyst showed relatively improved photocatalytic activity and stability in the degradation of RhB over the individual APO, NFO and APO/NFO materials. By the electrochemical and fluorescence measurements, the APO/MOF/NFO(20%) material also showed a larger transient photocurrent, lower impedance, and longer fluorescence lifetime (7.68 ns). Comparing the activity results with the characterization results, it was indicated that the photocatalytic activity depends on the rapid transfer of electrons from APO to NFO through the three-dimensional structure of the MOF. Furthermore, the possible mechanism for the photodegradation process of APO/MOF/NFO(20%) was proposed to illustrate excellent photocatalytic activity. The present study has paved a new way for using the attractive MOF in the design of a new and efficient system for organic dye degradation in wastewater.