A Novel Peroxymonosulfate Activation Process by Single-Atom Iron Catalyst from Waste Biomass for Efficient Singlet Oxygen-Mediated Degradation of Organic Pollutants

Single-atom dispersed catalysts (SACs) have attracted considerable attention in Fenton-like reactions because of their superior reactivity and stability. However, the complex and costly synthesis processes limit their practical applications in environmental protection. Herein, a facile and cost-effective single-atom iron catalyst (Fe-SA/NC) anchored on nitrogen-doped porous carbon was firstly fabricated by using waste biomass as a carbon source. The Fe-SA/NC catalyst exhibited outstanding performance with high turnover frequency toward antibiotics degradation via peroxymonosulfate activation. Radical quenching and electron paramagnetic resonance experiments revealed that Fe-SA/NC remarkably promoted 1O2 generation in PMS-assisted reaction. As indicated by experiment and density functional theory (DFT) calculations, FeN2O2 configuration serves as the active site. DFT calculations further presented the most rational generation route of 1O2 as PMS→OH*→O*→1O2. We also designed Fe-SA/NC embedded spherical pellets for contaminants elimination at device level. This work provides new guidance for the synthesis of SACs from waste biomass and its’ practical application in environmental remediation.