Bisthiourea immobilized UiO-66-NH₂ supported Fe₂O₃ nanoparticles to accelerate dual centers Fenton-like reaction

In this paper, an efficient catalyst UiO-66-BTU/Fe₂O₃ was synthesized by using bisthiourea modified zirconium-based metal organic framework (Zr-MOF). The UiO-66-BTU/Fe₂O₃ system features outstanding Fenton-like activity that is 22.84 times and 12.91 times larger than Fe₂O₃ and conventional UiO-66-NH₂/Fe₂O₃ system. It also exhibits good stability, broad pH range and recycle ability. Through comprehensive mechanistic investigations, we have ascribed the excellent catalytic performance of the UiO-66-BTU/Fe₂O₃ system to ¹O₂ and HO as the reactive intermediates, cause Zr centers can make complexation with Fe to form dual centers. Meanwhile, the CS on the bisthiourea can form Fe-S-C bonds with Fe₂O₃, reducing the redox potential of Fe(III)/Fe(II) and influencing the decomposing of H₂O₂, which indirectly regulate the interaction between Fe and Zr to accelerate electron transfer during the reaction. This work exhibits the design and understanding of the iron oxides incorporated in modified MOFs with excellent Fenton-like catalytic performance to remove phenoxy acid herbicides.