Constructing Zr/Fe-MOF-derived carbon intercalated MXene/Zr-Fe@C heterostructure for NSAIDs removal: Synergistic adsorption performance and mechanism studies in single and binary systems

The extensive use of non-steroidal anti-inflammatory drugs (NSAIDs), particularly diclofenac (DIC) and indomethacin (IND), poses escalating ecological and health risks due to incomplete degradation in water systems. Conventional remediation methods face challenges including low efficiency and toxic intermediate generation. Herein, we developed a novel MXene/Zr-Fe-MOF-derived carbon heterostructure (MXene/Zr-Fe@C) featuring bimetallic Zr/Fe active sites anchored on MXene nanosheets. The heterostructure design of MXene/Zr-Fe@C enables exceptional synergistic adsorption of NSAIDs from aqueous environments. Systematic adsorption experiments in single-component (DIC or IND) and binary (DIC+IND) systems revealed competitive adsorption behaviors and synergistic effects. MXene/Zr-Fe@C demonstrated satisfactory adsorption capacities (277.7 mg/g for DIC and 238.09 mg/g for IND, surpassing conventional adsorbents. These exceptional performances stem from the bimetallic site selectivity and synergistic domain interactions of MXene/Zr-Fe@C. The Zr/Fe@C provide selective coordination site, while MXene and carbon matrix promote the non-polar interaction with aromatic rings of NSAIDs. Remarkably, the composite exhibited excellent regenerability, retaining 83% of adsorption capacity after 54 regeneration cycles. Overall, the synergistic interfacial effects between MXene's conductive surfaces and ordered porosity of MOF-derived carbon enhance structural stability, efficient mass transfer and site accessibility. These findings establish MXene/Zr-Fe@C heterostructures as versatile platforms for NSAIDs remediation, providing foundational insights for sustainable water purification technologies addressing emerging pharmaceutical contamination challenges.