Molybdenum-mediated morphology and electronic structure engineering of self-supported Co₂N_0.67 to synergistically...

Designing self-supported catalysts with finely tailored cobalt-nitrogen configurations presents significant challenges in enhancing antibiotic degradation through peroxymonosulfate (PMS) activation. Herein, a self-supporting catalyst Mo-Co₂N_0.67@NF was synthesized through Mo-mediated morphological and electronic structure engineering combined with urea-assisted nitridation. The Mo doping induced the reconstruction of Co₂N_0.67 nanowires into a three-dimensional porous nanosheet architecture and optimized the Co-N coordination environment. This modification significantly strengthened the electronic interaction and interfacial electron transfer between Mo and Co sites, thereby remarkably enhancing the intrinsic PMS activation activity. The Mo-Co₂N_0.67@NF/PMS system achieved a 94.4% removal of tetracycline hydrochloride (TCH) within 30 min and a 42.98% total organic carbon mineralization within 100 min. Furthermore, it exhibited good stability across a wide pH range (3-9) and demonstrated strong anti-interference capabilities against common inorganic anions and humic acid. The catalyst also showed exceptional universality for various organic pollutants and outstanding reusability after five consecutive cycles. Mechanistic investigations revealed that TCH degradation was primarily governed by radical pathways in conjunction with non-radical pathways, proceeding through three degradation pathways involving thirteen intermediates, ultimately mineralizing into CO₂ and H₂O with significantly reduced ecotoxicity. This work offers an efficient strategy for regulating Co-N configurations and developing high-performance transition metal nitride catalysts for advanced oxidation processes in environmental remediation.