Facile synthesis of a novel Ag 3 PO 4 /MIL-100(Fe) Z-scheme photocatalyst for enhancing tetracycline degradation under visible light

In this work, a novel visible light–driven heterostructure Ag 3 PO 4 /MIL-100(Fe) composite photocatalyst was successfully synthesized via facile chemical deposition method at room temperature. Especially when the mass ratio of Ag 3 PO 4 was 20% of MIL-100(Fe) (APM-2), it displayed the best photocatalytic performance, for which the degradation rate of tetracycline (TC) in conventional environment was 6.8 times higher than that of bare MIL-100(Fe). In addition, the effects of the initial concentration and pH of the solution on the degradation of tetracycline were also studied, and the results showed that the degradation of tetracycline was more favorable in a weakly alkaline environment. The excellent performance of Ag 3 PO 4 /MIL-100(Fe) composites was attributed to the fact that on the basis of having adequate photocatalytic active sites, modifying MIL-100(Fe) with an appropriate amount of Ag 3 PO 4 particles can more effectively separate photogenerated electron–hole pairs. Five cycles of experiments showed that APM-2 has good photostability. Lastly, it was proved through quenching experiments that •O 2 − , h + , and •OH all played corresponding roles in the degradation process, and a possible Z-scheme heterostructure photocatalytic degradation mechanism was proposed.