Boosting photo-Fenton process enabled by ligand-to-cluster charge transfer excitations in iron-based metal organic framework

• Published in: Applied catalysis. B, Environmental Vol. 302; p. 120882
• Main Authors: Li, Wen-Qiang, Wang, Yi-Xuan, Chen, Jia-Qi, Hou, Nan-Nan, Li, Yuan-Ming, Liu, Xiao-Cheng, Ding, Rong-Rong, Zhou, Guan-Nan, Li, Qi, Zhou, Xiao-Guo, Mu, Yang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-03-2022; Elsevier BV
• Subjects: Charge efficiency; Charge transfer; Ciprofloxacin; Clusters; Contaminants; Excitation; Fe(III)/Fe(II) transformation; Fe-based metal organic frameworks; Iron; Irradiation; Ligand-to-cluster charge transfer excitations; Ligands; Light irradiation; Metal-organic frameworks; Nanorods; Photo-Fenton; Pollutant removal; Porphyrins; Radiation; Transformations; Photo-Fenton; Ligand-to-cluster charge transfer excitations; Fe(III)/Fe(II) transformation; Fe-based metal organic frameworks
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2021.120882

Iron-based metal organic frameworks (MOFs) are widely adopted to mediate heterogeneous photo-Fenton reaction, but poor charge separation efficiency in iron-oxo clusters of MOF usually results in the dull Fe(III)/Fe(II) transformation. In this study, ligand-to-cluster charge transfer (LCCT) excitations were first introduced to photo-Fenton process toward accelerating Fe(III)/Fe(II) transformation by constructing new iron-based MOF nanorods with porphyrin ligand (Fe-TCPP). Fe-TCPP with LCCT excitations showed a maximum kinetic constant of 0.23 min-1 for ciprofloxacin (CIP) degradation at neutral pH under visible light irradiation, which is remarkably better than most of the state-of-the-art photocatalysts. Experimental and theoretical analyses collaboratively verify that LCCT excitations within Fe-TCPP dramatically accelerate Fe(III)/Fe(II) transformation, which generate more ∙OH for quick CIP elimination. Additionally, this LCCT excitations strategy is also effective for the photo-Fenton-like system induced by copper-based MOFs. Our study presents a novel strategy to intensify MOFs based photo-Fenton/Fenton-like processes, upon which the high-efficiency contaminant removal is expected.
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•LCCT excitations were first introduced to MOFs based photo-Fenton process.•Fe-TCPP with LCCT excitations displayed best antibiotic degradation performance.•LCCT excitations occurrence within Fe-TCPP was identified by different methods.•LCCT excitations within Fe-TCPP speed Fe(III)/Fe(II) transformation and ∙OH generation.