Copper-Based MOF-Derived Core–Shell Materials via N/P/S Ternary Doping for Peroxymonosulfate Activation: Efficient Degradation and Removal of Sulfamethazine

Sulfamethazine (SMT) contamination in aquatic environments and its propensity to induce antibiotic resistance pose critical risks to ecosystems and public health, necessitating effective remediation strategies. Here, we develop a MOF-derived copper core-shell activator, Cu-MOFs400@PSN, by coating a calcined Cu-MOF derivative (Cu-MOFs400) with a nitrogen/phosphorus/sulfur-doped shell and systematically evaluate its peroxymonosulfate (PMS) activation performance toward SMT degradation. Comprehensive characterization confirms successful N/P/S incorporation and the formation of a smooth spherical core-shell architecture that enhances chemical stability; the Cu-MOFs400@PSN/PMS system achieves complete SMT removal within 120 min and maintains 99.33% efficiency after five reuse cycles. Bicarbonate markedly promotes degradation, whereas chloride, nitrate, and phosphate exert negligible interference, indicating strong tolerance to common background ions. Radical-quenching tests identify singlet oxygen (¹O₂) and superoxide (•O₂^-) as the dominant reactive species, with minor contributions from sulfate and hydroxyl radicals; the system facilitates complete SMT mineralization and reduces resistance-inducing intermediates. These results highlight Cu-MOFs400@PSN as a robust and reusable PMS activator for practical remediation of SMT-contaminated waters and mitigation of antibiotic-resistance risks.