Impregnation of Single-Atom Iron from Metallosurfactants onto MOF-Derived Porous N-Doped Carbon for Efficient Wastewater Treatment via Peroxymonosulfate Activation

Herein, a Fe-MOF-derived single iron atom impregnated on porous N-doped carbon (Fe SAC /NC) was synthesized using an iron-based metallosurfactant (FeCTAC) as the precursor. The formation of isolated single atoms and their surrounding environment after pyrolysis at 900 °C was confirmed by XPS and EXAFS analysis. The use of FeCTAC facilitated the exposure of more single iron atoms on the porous NC matrix and prevented their aggregation, as verified by elemental analysis and HAADEF-TEM. The resulting Fe SAC /NC was applied in the Fenton reaction for the degradation of tetracycline (TC) by activating peroxymonosulfate (PMS). It achieved 92% TC removal in 40 min compared to only 23% with PMS alone. Free radical scavenging experiments indicated that a nonradical pathway, involving singlet oxygen and electron transfer, dominated the degradation process. Additionally, pyrrolic and graphitic nitrogen sites in the NC matrix contributed significantly to TC adsorption. This exceptional catalytic performance provides valuable insights for designing highly efficient catalysts for wastewater treatment.