Novel mulberry-like N, S co-doped carbon-embedded iron carbide (FeC@NSC) composite selectively activates peroxymonosulfate for Rhodamine B degradation via non-radical dominated pathways

Advanced oxidation processes (AOPs) based on peroxymonosulfates (PMS) are considered effective wastewater treatment. However, activation of PMS remains challenging. Herein, a mulberry-like nitrogen and sulfur (N, S) co-doped carbon-embedded iron carbide composite catalyst (FeC@NSC) was prepared by a one-pot approach to activate PMS and degrade organic pollutants (for example Rhodamine B). The introduction of S atoms shifted the PMS activation mechanism on FeC@NSC towards a non-radical pathway. It is found that within 12 min, the FeC@NSC can completely degrade 50 mg L −1 of Rhodamine B, with a degradation reaction kinetic constant of 0.386 min −1 , which is 3.64 times that of the FeC 3 @NC/PMS system. Quenching tests, electron paramagnetic resonance (ESR), and electrochemical experiments revealed that non-radical species ( 1 O 2 , Fe IV ) are the main active species, accompanied by electron transfer processes. Furthermore, water quality interference experiments and cycling experiments verified the outstanding catalytic activity and structural stability of the synthesized catalyst. We believe this work sheds more light on the rational design of new carbon based catalysts able to regulate non-radical PMS activation pathways for effective pollutants degradation.