Single atom Cu anchored on porous polymeric carbon nitride toward peroxymonosulfate activation for emerging pollutants degradation

Single-atom catalysts (SACs) have been increasingly investigated in Fenton-like reactions for emerging pollutants degradation. Herein, single atom Cu anchored on porous polymeric carbon nitride (SA-Cu/PCN-α) was prepared for peroxymonosulfate (PMS) activation on tetracycline (TC) removal. The as-prepared composites were comprehensively characterized by SEM, TEM, XRD, XPS, and EDS, confirming the successful incorporation of Cu single atoms and the formation of a porous heterostructure. SA-Cu/PCN-α efficiently activated peroxymonosulfate (PMS) to degrade TC, with a pseudo-first-order rate constant k of 0.843 min⁻¹-18.7-fold higher than that of pure PCN (0.045 min⁻¹). Mechanistic studies revealed that Cu single atoms modulated the electronic structure of PCN, promoting charge separation and generating abundant reactive oxygen species (ROS, primarily 1 O 2 and O 2 •-). Static experiments indicated that the degradation efficiency remained above 80% under wide ranges of pH (3-11) and PMS dosage (0.5-2.0 mM) within 10 min. The catalyst retained 80% activity after five cycles, demonstrating its stability.Overall, this work designs Cu SACs with promising implications for wastewater treatment.