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• N,O,S-codoped carbon based Co SAC was synthesized for effective PMS activation. • Rapid ibuprofen degradation (k , 0.4 min−1) with excellent reusability is obtained. • Co sites derive both radical (SO 4 − and OH) and non-radical 1O 2 in activating PMS. • Electron-rich O and S sites contribute to PMS reduction to generate SO 4 − and OH. • Exceptional resilience and efficiency in oxidizing diverse organics are achieved. Single-atom catalysts (SACs) are charming for heterogeneous Fenton-like processes due to their unique and adjustable electron structure. Developing novel SACs and elucidating their mechanisms are critical for the development of water purification techniques. Herein, we present an N,O,S-codoped carbon based Co SAC (Co SA -N-C O,S) synthesized by anchoring isolated Co atoms onto porous carbon derived from low-cost protic salt. This catalyst exhibits significant efficiency in activating peroxymonosulfate (PMS) for rapid ibuprofen (IBU) degradation, achieving approximately 98.2 % within 10 min at a concentration of 0.2 g/L catalyst and 2 mM PMS, under ambient pH and at 30 °C, and demonstrates excellent reusability. Intensive studies reveal that the highly active atomic Co sites are favorable for activating PMS to produce both radical (SO 4 − and OH) and nonradical 1O 2 , while the electron-rich O and S sites contribute to PMS reduction to generate SO 4 − and OH. The Co SA -N-C O,S /PMS system leverages the synergy between radical and nonradical oxidation across multiple active sites, resulting in exceptional resistance to interference and high efficiency in degradation and mineralization of diverse organic pollutants. This study develops a novel single-atom catalyst for wastewater treatment and elucidates the mechanism behind PMS activation by a carbon-based cobalt single atom catalyst. [ABSTRACT FROM AUTHOR]

• N,O,S-codoped carbon based Co SAC was synthesized for effective PMS activation. • Rapid ibuprofen degradation (k , 0.4 min−1) with excellent reusability is obtained. • Co sites derive both radical (SO 4 − and OH) and non-radical 1O 2 in activating PMS. • Electron-rich O and S sites contribute to PMS reduction to generate SO 4 − and OH. • Exceptional resilience and efficiency in oxidizing diverse organics are achieved. Single-atom catalysts (SACs) are charming for heterogeneous Fenton-like processes due to their unique and adjustable electron structure. Developing novel SACs and elucidating their mechanisms are critical for the development of water purification techniques. Herein, we present an N,O,S-codoped carbon based Co SAC (Co SA -N-C O,S) synthesized by anchoring isolated Co atoms onto porous carbon derived from low-cost protic salt. This catalyst exhibits significant efficiency in activating peroxymonosulfate (PMS) for rapid ibuprofen (IBU) degradation, achieving approximately 98.2 % within 10 min at a concentration of 0.2 g/L catalyst and 2 mM PMS, under ambient pH and at 30 °C, and demonstrates excellent reusability. Intensive studies reveal that the highly active atomic Co sites are favorable for activating PMS to produce both radical (SO 4 − and OH) and nonradical 1O 2 , while the electron-rich O and S sites contribute to PMS reduction to generate SO 4 − and OH. The Co SA -N-C O,S /PMS system leverages the synergy between radical and nonradical oxidation across multiple active sites, resulting in exceptional resistance to interference and high efficiency in degradation and mineralization of diverse organic pollutants. This study develops a novel single-atom catalyst for wastewater treatment and elucidates the mechanism behind PMS activation by a carbon-based cobalt single atom catalyst. [ABSTRACT FROM AUTHOR]

In this work, we revealed a dual-pathway nonradical oxidation (NRO) system catalyzed by Ni single atom catalyst (NiN 4) accommodated in the carbon nitride substrate. The monatomic Ni coordinated with four N atoms (Ni-N 4) is determined as the dynamic catalytic center for peroxymonosulfate (PMS) activation, showing an exceptional specific rate constant of 3.34 min−1 g−2 L−2 (29.7 times that of CN/PMS system) in oxidizing bisphenol A and other refractory organics. In situ Raman, X-ray absorption, and electrochemical analyses as well as theoretical simulations demonstrate that the Ni-N 4 sites exhibit strong interaction with PMS benefited from the modulated electronic structures, resulting in nonradical surface-bonding active complexes (NiN 4 -PMS*) and deuterogenic high-valent Ni(IV)-Oxo species. The dual-pathway NRO process will spontaneously coordinate both electron transfer process via CN matrix and direct electron transfer by Ni(IV)-Oxo for selective organic oxidation with excellent anti-interference ability and adaptability. [Display omitted] • A novel dual-pathway NRO is systematically revealed in a PMS/NiN 4 system. • NiN 4 /PMS exhibits efficiently selective oxidation of different refractory organics. • Ni-N 4 with highly modulated electronic structures exhibits strong interaction with PMS. • NiN 4 -PMS* and high-valent Ni(IV)-Oxo contribute to dual-pathway NRO process. • Dual-pathway NRO renders the applicability of NiN 4 /PMS in wide water matrixes. [ABSTRACT FROM AUTHOR]

Hybrid systems combined eletrocatalysis and Fenton-like process attract a lot of attention due their outstanding performance and unique mechanism. Here, we proposed an efficient, cost-effective, and versatile electrochemical activation (ECA) system for efficient water purification, and intensively studied the synergistic effects between electrocatalysis and peroxymonosulfate (PMS)-based advanced oxidation. The ECA system achieved complete removal of 20 ppm tetracycline hydrochloride (TCH) in 15 min, with a rate constant of 0.338 min−1. Its performance was assessed across various operational parameters (PMS dosage, pH, applied voltage, electrode interval, temperature, co-existed ions, biomass, different oxidants), demonstrating its broad applicability and stability. Excellent degradation and mineralization for other 12 kinds of refractory organic pollutants were also achieved. The outstanding performance can be attributed to the synergistic effect in the system, in which electrocatalytic reduction of dissolved oxygen generated H 2 O 2 and O 2 •-, boosting the number of reactive species, such as 1O 2 , by interacting with PMS. Furthermore, the presence of organic matter promotes electron transfer, amplifying the system's degradation capability. These findings not only highlight the ECA system's effectiveness in organic pollutant removal but also offer insights into the underlying degradation mechanisms, paving the way for future advancements in water purification technologies. [Display omitted] • An efficient, cost-effective, and versatile ECA system is proposed for efficient water purification. • 20 ppm TCH can be completely removed in 15 min with a rate constant of 0.338 min−1. • Excellent organic elimination is achieved under a broad operation conditions. • Dissolved oxygen contributes to the generation of radicals and organic oxidation. • Synergistic effect between electrocatalysis and peroxonosulfate activation is elucidated. [ABSTRACT FROM AUTHOR]