Enhanced photo-Fenton degradation of tetracycline hydrochloride by 2, 5-dioxido-1, 4-benzenedicarboxylate-functionalized MIL-100(Fe)

Heterogeneous photo-Fenton technology has drawn tremendous attention for removal of recalcitrant pollutants. Fe-based metal-organic frameworks (Fe-MOFs) are regarded to be superior candidates in wastewater treatment technology. However, the central metal sites of the MOFs are coordinated with the linkers, which reduces active site exposure and decelerates H2O2 activation. In this study, a series of 2, 5-dioxido-1, 4-benzenedicarboxylate (H2DOBDC)-functionalized MIL-100(Fe) with enhanced degradation performance was successfully constructed via solvothermal strategy. The modified MIL-100(Fe) displayed an improvement in photo-Fenton behaviors. The photocatalytic rate constant of optimized MIL-100(Fe)-1/2/3 are 2.3, 3.6 and 4.4 times higher compared with the original MIL-100(Fe). The introduced H2DOBDC accelerates the separation and transfer in photo-induced charges and promotes Fe(II)/Fe(III) cycle, thus improving the performance. •OH and •O2− are main reactive radicals in tetracycline (TCH) degradation. Dealkylation, hydroxylation, dehydration and dealdehyding are the main pathways for TCH degradation.