Targeted degradation of aromatic pollutants in complex matrices via selective electrocatalytic O2 activation to 1O2 over O-doped Fe single-atom catalysts.

The interference from complex matrices in realistic water environments significantly inhibits the degradation kinetics of target pollutants. Herein, we propose an electronic reconfiguration strategy by introducing O into the coordination sphere of Fe-N4-C sites (Fe-NC(O)) to achieve selective electrocatalytic O2 activation to singlet oxygen (1O2). The electrophilic 1O2 can selectively degrade of electron-rich compounds. Mechanistic studies reveal that the electron-withdrawing O depletes the valence electron density in the d-orbitals of Fe, thereby weakening *OOH adsorption to inhibit O-O bond scission. Consequently, Fe-NC(O) achieves a 22.45-fold enhancement in 1O2 yield compared to the Fe single atom catalyst without O doping. Notably, 1O2 accounts for 93 % of the total reactive oxygen species in the Fe-NC(O) system. The Fe-NC(O) achieves rapid degradation of aromatic pollutants (phenol, bisphenol A, p-chlorophenol, and sulfamethoxazole) with high mineralization efficiency (>80 %) in wastewater containing coexisting natural organic matter and inorganic ions. Furthermore, it realizes the energy-efficient decontamination of real medical wastewater with a specific energy consumption of only 6.85 kWh kg(COD)-1. This work demonstrates a feasible strategy for efficient 1O2 production, advancing electrochemical advanced oxidation processes for water decontamination.