Designing a bimetallic Fe,Co-MOF supported Sn-doped BiFeO3/CdS dual Z-scheme heterojunction for boosted visible light gatifloxacin degradation: Coupling experimental performance with DFT insights

The designing of defect-engineered heterojunction supported via porous framework material capable of maximizing solar energy utilization and enhancing redox efficiency is the burning scientific issue in advanced photocatalysis. Based on the literature survey, it is evident that incorporation of bimetallic MOF within the defect-engineered junction requires in-depth investigation to make a potential photocatalytic system. To fill the research gap, this study successfully constructed a novel Fe,Co-MOF assisted bandgap engineered Sn-doped BFO/CdS heterojunction which increases the interfacial charge dynamics and photo redox functionality for enhanced GAT removal. The dual Z-scheme charge transfer pathway aids in preserving strong redox potentials with superoxide (O<inf>2</inf>^•-) and hydroxyl (^•OH) radicals being the most dominating reactive species for achieving 95.7% photodegradation of GAT antibiotic within 90 min of light illumination. The subsequent rate of the reaction (0.02128 min⁻¹) indicated a multi-fold increase in case of Sn-BFO/CdS/Fe,Co-MOF ternary system compared to bare samples. The 1,4-BDC organic linker in Fe,Co-MOF enhances the adsorption behaviour via hydrogen bonding, π–π interactions between aromatic rings and quinolone rings, and electrostatic interaction between the catalyst surface and GAT molecule. As a result, these synergistic interactions promote the efficient degradation performance. The structural investigations of GAT utilizing Density Functional Theory (DFT) results and the primary intermediates were identified utilizing Liquid Chromatography - Mass Spectrometry (LC-MS) to elucidate five photodegradation pathways for GAT. Lastly, the research highlights the magnetic separability, excellent structural stability, and reusability over four consecutive cycles, underscoring its durability and applicability in real-world environmental remediation in accordance with roadmap for sustainable future.