Molecular oxygen activation with ferrous iron-tetrapolyphosphate complex for efficient degradation of antibiotic sulfadimidine

The escalating prevalence of antibiotic resistance induced by pharmaceutical misuse poses severe threats to global ecosystems and human health. Herein, we demonstrate a molecular oxygen (O2) activation strategy with using tetrapolyphosphate-ferrous complex as an activating reagent (Fe2+/TPP/O2) for effective sulfamethazine (SMZ) degradation. Intriguingly, the Fe2+/TPP/O2 system exhibited a 31-fold enhancement in SMZ degradation kinetics compared to the conventional Fe2+/O2 counterpart. Through spectroscopic and mass spectrometric techniques, we revealed that TPP complexation could modulate the Fe2+ redox behavior — through the formed Fe2+-TPP complex to elevate Fe2+ reducibility and simultaneously drive O2 activation in a sequential single-electron reduction routine (O2 → ·O2− → H2O2). Subsequent Fenton-like reaction decomposed the in situ formed H2O2 into hydroxyl radicals (·OH) to trigger the SMZ degradation and its further mineralization. This work offers a facile strategy to construct a Fenton-like system for efficient antibiotics contamination treatment.