Fe-O-P bond in MIL-88A(Fe)/BOHP heterojunctions as a highway for rapid electron transfer to enhance photo-Fenton abatement of enrofloxacin

MIL-88A(Fe)/BOHP (MxBy) heterojunctions were firstly fabricated via a ball-milling method, which were adopted as catalysts to activate hydrogen peroxide (H2O2) with the aid of visible light illumination to build a heterogeneous photocatalysis-Fenton-like synergetic system. The catalytic degradation efficiency of enrofloxacin (ENR) (10 mg/L) in the optimal M3B7/Vis/H2O2 system reached nearly 100 % with appreciable mineralization ability. Experimental and theoretical results co-unraveled that the formation of interfacial Fe-O-P chemical bonds between MIL-88A(Fe) and BOHP effectively reduced the charge transfer energy barrier (59.41-26.69 eV) and migration distance (3.104-1.917 angstrom), allowing the photo-generated carriers to be efficiently separated in space and improving the activation efficiency of H2O2 for producing more active species. Impressively, the constructed M3B7/Vis/H2O2 system was a cost-optimal and green technology for antibiotic wastewater treat-ment based on Electrical Energy per Order (EE/O) concept, life cycle assessment (LCA) and quantitative struc-ture-activity relationship (QSAR) analysis.

Automated summary

MIL-88A(Fe)/BOHP (MxBy) heterojunctions were fabricated as catalysts to activate hydrogen peroxide (H2O2) through visible light illumination. The catalytic degradation efficiency of enrofloxacin (ENR) in the M3B7/Vis/H2O2 system reached almost 100% with good mineralization ability. The formation of interfacial Fe-O-P chemical bonds between MIL-88A(Fe) and BOHP effectively reduced the charge transfer energy barrier and migration distance, leading to efficient separation of photo-generated carriers and improved activation efficiency of H2O2.