Reactive oxygen species-mediated UV photocatalytic removal of cyclophosphamide by Fe3O4/Ti3C2Tx

• Abiotic probes confirmed •OH, O₂•⁻ generation by Fe 3 O 4 /Ti 3 C 2 T x . • Fe 3 O 4 /Ti 3 C 2 T x composite efficiently degraded CP under UV light. • Fe 3 O 4 decoration enhanced charge separation and CP adsorption affinity. • An 83.4 ± 1.1 % CP degradation was achieved in 120 min with good reusability. • LC–MS/MS showed hydroxylation and hydrolysis as the main degradation pathways. Cyclophosphamide (CP), a widely used cytostatic drug, poses significant environmental challenges due to its persistence and potential toxicity in aquatic systems. In this study, the photocatalytic and optical properties of a magnetic MXene (Fe 3 O 4 /Ti 3 C 2 T x ) composite were systematically investigated under UV illumination. Abiotic probe assays confirmed the generation of reactive oxygen species (ROS), including hydroxyl radicals (•OH) and superoxide (O₂•⁻), thereby validating the material's intrinsic photocatalytic activity. Photocatalytic degradation experiments demonstrated that decorating MXene (Ti 3 C 2 T x ) with iron oxide (Fe 3 O 4 ) enhanced light utilization, promoted charge separation, and improved CP adsorption affinity. Structural analysis further revealed partial surface oxidation of Ti 3 C 2 T x into TiO 2 , contributing to its photocatalytic activity. Under optimized conditions (50 mg/L catalyst dose, pH 5.6), the composite achieved 83.4 ± 1.1% CP degradation within 120 min and retained performance over four cycles, confirming stability and reusability. The synergistic effect of Fe²⁺-driven Fenton-like reactions, photoactive TiO 2 domains, and the conductive Ti 3 C 2 T x matrix ensured sustained ROS production and suppressed electron-hole recombination. Liquid chromatography–mass spectrometry (LC–MS/MS) identified three transformation products (TPs), with hydroxylation and hydrolysis as the dominant degradation pathways.