Catalytic Activity Enhancement by P and S Co-Doping of a Single-Atom Fe Catalyst for Peroxymonosulfate-Based Oxidation

•P & S co-doped single-atom Fe catalyst exhibited excellent performance in PMS activation.•FeⅤN4 = O intermediate was the dominant reactive species in the FeSA-NPS@C/PMS system.•Electrostatic effect between pollutant and FeⅤN4 = O facilitated the degradation.•P & S atom co-doing effectively altered the electronic structure of the FeN4 sites.•DFT calculation elucidated the mechanism of catalyst enhancement via P & S doping.