Construction of an MIL-101(Fe)/layered bimetallic oxide heterojunction for enhanced ciprofloxacin removal

Abstract

A novel MIL-101(Fe)/ZnCrZr-LBMO heterojunction was successfully constructed and used for the removal of ciprofloxacin (CIP) in this work. The MIL-101(Fe)/ZnCrZr-LBMO composite exhibited significantly enhanced photocatalytic degradation activity, with reaction rates approximately 3.4 and 3.1 times faster than those observed with pristine MIL-101(Fe) and ZnCrZr-LBMO, respectively. The effect of different amounts of ZnCrZr-LBMO, sample pH, CIP concentration, inorganic cations, and anions on CIP removal was investigated, and the possible intermediates and degradation pathways of CIP were speculated. The·O₂⁻ radicals dominated CIP degradation, with minor contributions from ¹O₂, h⁺, and ·OH radicals. The composite exhibited high removal rates for CIP (94.7%), ofloxacin (86.8%), and tetracycline (96.3%), respectively, within 60 min of light irradiation, and excellent reusability, retaining over 85.1% CIP degradation rate after five cycles. Our work provides a new reference to construct highly efficient and easily recyclable MIL-101(Fe)/ZnCrZr-LBMO photocatalysts for the removal of antibiotic pollutants, promising advancements in real water treatment applications.