Phosphotungstic acid encapsulated in MIL‐53(Fe) as efficient visible‐light photocatalyst for rhodamine B degradation

Materials based on phosphotungstic acid (H 3 PW 12 O 40 , HPW) encapsulated in metal organic framework MIL‐53(Fe) were prepared by a simple solvothermal method. The as‐synthesized samples were characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectra, and UV–vis diffuse reflectance spectroscopy method. The resulting materials were evaluated in the photodecomposition of cationic dye Rhodamine B (RhB) under visible light irradiation. A Light‐emitting diodes lamp was used as visible light source. The results showed that the composites exhibited better photocatalytic activities than pure materials. A possible photocatalytic reaction mechanism has been investigated. The formation of active oxygen species such as • OH and • , which are detected during the degradation of RhB, is proposed to be responsible for the degradation of RhB. In addition, the HPW@MIL‐53(Fe) photocatalyst exhibited good chemical stability after five consecutive degradation cycles. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1342–1350, 2017