Reconstructing the coordination environment of single atomic Fe-catalysts for boosting the Fenton-like degradation activities

This study develops an advanced single-atomic iron-loaded graphitic carbon nitride (Fe 1 /CN) with unparalleled efficiency for converting peroxymonosulfate (PMS) to oxidants for water treatment. We found that acid-etching of Fe 1 /CN leads to the reconstruction of conventional Fe 1 –N 4 to Fe 1 –C 2 N 1 active sites. The acid-induced Fe 1 –C 2 N 1 sites are more favorable for PMS binding and have a lower energy barrier for 1 O 2 production. The precise tuning of the coordination environment bestows the acid-etched Fe 1 /CN with 29 times higher rate constants of bisphenol A degradation than its pristine counterparts. Further, the particulate catalysts were assembled into a self-supported catalytic membrane, which demonstrates excellent long-term durability throughout 170 h flow-through tests in both synthetic and real wastewater. This work provides pivotal insights into improving PMS activation activity by regulating the coordination environment around single atomic Fe sites. The engineering innovation laid the groundwork for new point-of-use water treatment devices. ● Acid-etching re-arranges the coordination of single atomic Fe-catalyst (Fe SACs). ● The rearrangement induces the active site transformation from Fe 1 –N 4 to Fe 1 –C 2 N 1 . ● Fe–C 2 N 1 lowers the barrier *OH→*O→ 1 O 2 and yields 8.5 times of 1 O 2 than Fe 1 –N 4 . ● Fe 1 –C 2 N 1 performed much faster than Fe 1 –N 4 for atrazine and bisphenol A removal. ● 90% of bisphenol A was steadily removed in a continuous flow reactor in 170 h.