Magnetically recyclable Ti3C2–Co nanoreactor with spatial confinement for enhanced peroxymonosulfate activation and ciprofloxacin degradation

Antibiotic residues, especially ciprofloxacin (CIP), pose ecological and health risks due to their persistence and poor removal by conventional wastewater treatment. Herein, a magnetically recyclable Ti 3 C 2 –Co nanoreactor was synthesized via a molten-salt in situ etching strategy for efficient peroxymonosulfate (PMS) activation and CIP degradation. The confined Ti 3 C 2 –Co architecture promotes local enrichment of PMS and CIP near Co active sites, thereby enhancing interfacial oxidation and reactive oxygen species (ROS) utilization. Density functional theory (DFT) calculations revealed that Ti 3 C 2 –Co strengthened PMS adsorption with an adsorption energy of −1.17 eV and elongated the O–O bond to 1.633 Å, confirming facilitated PMS activation and charge transfer. The Ti 3 C 2 –Co/PMS system achieved 99% CIP degradation within 30 min, maintained high activity over a broad initial pH range of 3–11, and removed more than 85% of CIP in real water matrices. Radical and non-radical pathways involving SO 4 − ·, ·OH, O 2 – ·, and 1 O 2 jointly contributed to CIP degradation, while Co 2+ /Co 3+ cycling and Ti 3 C 2 –Co interfacial electron transfer synergistically promoted PMS activation. The catalyst retained 90.85% activity after four cycles, demonstrating its potential for practical wastewater treatment.