Bimetallic Fe/Ti-Based Metal-Organic Framework for Persulfate-Assisted Visible Light Photocatalytic Degradation of Orange II

Amine-functionalized bimetallic Fe/Ti-based metal-organic frameworks (Fe/Ti-MOF-NH2) were synthesized via the solvo-thermal method and used as photocatalysts and activators for persulfate (PS)-assisted visible light photocatalytic degradation of Orange II. Nearly 100% of Orange II was removed within 10 min in the Fe/Ti-MOF-NH2(3:1)/PS/Vis process, while only 10.7% and 70.9% of Orange II were removed in Fe/Ti-MOF-NH2(3:1)/Vis and Fe/Ti-MOF-NH2(3:1)/PS processes within 10 min, respectively. Therefore, the synergistic effect of PS activation and visible light photocatalysis was demonstrated by the Fe/TiMOF-NH2(3:1) composite. The enhanced photocatalytic activity of the photocatalyst can be attributed to the efficient electrons transfer by Fe3+/Fe2+ and Ti4+/Ti3+ redox cycles, activation of PS by photogenerated electrons to produce sulfate radicals (SO4 center dot-), and increased formation of hydroxyl radicals ((OH)-O-center dot). Concurrently, the Fe/Ti-MOF-NH2(3:1) photocatalyst also exhibited good reusability and stability in the photocatalytic reaction system.