Persulfate activation by two-dimensional MoS2 confining single Fe atoms: Performance, mechanism and DFT calculations

Developing efficient catalysts for persulfate (PS) activation is important for the potential application of sulfate-radical-based advanced oxidation process. Herein, we demonstrate single iron atoms confined in MoS2 nanosheets with dual catalytic sites and synergistic catalysis as highly reactive and stable catalysts for efficient catalytic oxidation of recalcitrant organic pollutants via activation of PS. The dual reaction sites and the interaction between Fe and Mo greatly enhance the catalytic performance for PS activation. The radical scavenger experiments and electron paramagnetic resonance results confirm and SO4 center dot- rather than HO center dot is responsible for aniline degradation. The high catalytic performance of Fe0.36Mo0.64S2 was interpreted by density functional theory (DFT) calculations via strong metal-support interactions and the low formal oxidation state of Fe in FexMo1-xS2.FexMo1-xS2/PS system can effectively remove various persistent organic pollutants and works well in a real water environment. Also, FexMo1-xS2 can efficiently activate peroxymonosulfate, sulfite and H2O2, suggesting its potential practical applications under various circumstances.