Oriented SingletOxygen Generation via Molecular OxygenActivation on O‑Doped FeS₂ for the Robust AntibioticsRemediation

The widespread occurrence of antibiotics in the natural aquatic environment requires urgent remediation. The promising oxidation processes typically generate hydroxyl radicals (·OH) with the addition of chemical oxidants; however, they suffer from limited removal efficacy due to excessively undesired depletion of ·OH by coexisting environmental substances. Hence, this study proposed to address the above challenges by the oriented generation of singlet oxygen (¹O₂) from oxygen molecules (O₂). Guided by DFT calculation, the adsorption capacity and subsequential activation of O₂ were promoted through doping O on FeS₂ (FeS₂-O), leading to the oriented production of ¹O₂ with a 46.87-fold higher exposure than ·OH, with visible-light irradiation-trigged photogenerated electrons to facilitate the activation process. The FeS₂-O/O₂ system exhibited a remarkedly enhanced remediation efficiency of antibiotics, with a 6.62-fold increase in kinetic constant compared to pristine FeS₂. In addition, ¹O₂-mediated antibiotic remediation demonstrated robust performance across various water qualities, with a great potential to reduce ecotoxicological risks. We developed an external oxidant-free technique for the directed production of ¹O₂ from O₂ to effectively degrade and detoxify antibiotics in aquatic environments, providing new insights for natural water remediation.