Adsorption or photocatalysis? Engineering BiOi with metalorganic framework CAU-17 and microporous organic polymer MOP-CH2EDA to enhance ciprofloxacin removal from water

Abstract

Herein we report the fabrication of binary and ternary BiOI-based composites incorporating the metal-organic framework CAU-17 and the amine-functionalized microporous organic polymer MOP-CH₂EDA, designed to enhance both adsorption and photocatalytic degradation of ciprofloxacin (CIP). The materials were synthesized via an in-situ solvothermal route and extensively characterized to establish structure-property relationships. Ternary composites showed nice performance in both adsorption and photocatalysis, however dependent on the environmental conditions (pH of the reaction mixture) and several reactive oxygen species were found to play a role in CIP degradation.HPLC-MS analysis revealed multiple pH-dependent degradation pathways, confirming the inherent complexity of CIP transformation. These findings demonstrate that adsorption and photocatalysis act as complementary, sequential processes rather than competing ones. Overall, the work underscores both the potential and the current limitations of BiOI/MOF/MOP composites as multifunctional platforms for antibiotic removal and calls for unified assessment criteria in the field of photocatalytic water treatment.