Abstract
Highly efficient single atom catalysts are critical to substantially promote for peroxymonosulfate (PMS) activation to organic pollutant degradation, but it remains a challenge at present. Herein, single atom Mn anchored on N-doped porous carbon (SA-Mn-NSC) was synthesized by ball milling of Mn-doped carbon nitride and spirulina biochar to dominantly activate PMS. The precursor of carbon nitride and spirulina possessed a strong coordinating capability for Mn(II), facilitating the formation of highly dispersed nitrogen-coordinated Mn sites (Mn-N4). The SA-Mn-NSC catalyst exhibited high activity and stability in the heterogeneous activation of PMS to degrade a wide range of pollutants within 10 min, showing an outstanding degradation rate constant of 0.31 min−1 in enrofloxacin (ENR) degradation. The high surface density of Mn-N4 sites and abundant interconnected meso–macro pores were highly favorable for activating PMS to produce 1O2 and high-valent manganese (Mn(IV)) for pollutant degradation. This work offers a new pathway of using a low-cost and easily accessible single-atom catalysts (SACs) and could inspire more catalytic oxidation strategies.
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•The spirulina and carbon nitride conversion to single atom Mn via ball milling and pyrolysis.•The SA-Mn-NSC catalyst displays effective PMS activation for organic pollutant removal.•MnN4 sites acts as a shuttle that mediates the electron transfer from organic pollutant to PMS.•The redox cycle of Mn(IV)/Mn(III) in the surface of catalyst was identified.