Fabrication of Bi2Sn2O7@MIL-100(Fe) composite photocatalyst with enhanced superoxide-radical-dominated photocatalytic activity for ciprofloxacin degradation

A novel Bi 2 Sn 2 O 7 @MIL-100(Fe) composite photocatalyst was fabricated by loading Bi 2 Sn 2 O 7 nanoparticles on the surface of mesoporous MIL-100(Fe). The structure-property relationships of such composite photocatalyst were studied. The results exhibit that the formed Bi 2 Sn 2 O 7 @MIL-100(Fe) heterojunction promote the separation of photo-generated carriers, leading to the enrichment of photo-generated electrons on MIL-100(Fe). Meanwhile, MIL-100(Fe) can provide more active sites for photocatalytic reaction due to its extraordinary specific surface area. Therefore, the Bi 2 Sn 2 O 7 @MIL-100(Fe) composite photocatalyst exhibits excellent superoxide-radical-dominated photocatalytic activity and is more propitious to degrading the contaminants such as ciprofloxacin, which can be efficiently degraded in the absence of superoxide radicals. The Bi 2 Sn 2 O 7 @MIL-100(Fe) composite reveals enhanced photocatalytic activity for degrading ciprofloxacin with rate constant (0.0143 min −1 ) 1.96 and 3.86 times higher than that of pure MIL-100(Fe) (0.0073 min −1 ) and pure Bi 2 Sn 2 O 7 (0.0037 min −1 ), respectively.