Carbon nanotube-modified Fe-based catalysts for enhanced peroxymonosulfate activation and degradation of 2,4,6-trichlorophenol: Performance and mechanism

This study proposes a strategy for constructing catalysts based on carbon nanotube (CNT)-regulated pore structures. By coating CNTs onto the outer surface of a metal-organic framework, a series of composite catalysts (PCC-x) were successfully prepared. The introduction of CNTs not only optimized the pore environment of the catalyst, but also established continuous electron-transfer pathways, thereby promoting interfacial charge transfer and peroxymonosulfate (PMS) activation. Under the conditions of 0.6 g/L catalyst, 2 mmol/L PMS, and 10 mg/L 2,4,6-trichlorophenol (2,4,6-TCP), PCC-5 exhibited the best catalytic performance, achieving a removal efficiency of 95.1% for 2,4,6-TCP. The corresponding apparent rate constant is 1.75 times higher than that of the non-composite catalyst (NPC). Electrochemical impedance spectroscopy showed that the charge-transfer resistance of PCC-5 was 418.8 Ω, which was 17.2% lower than that of NPC (506.0 Ω), confirming that CNT incorporation effectively promoted interfacial electron transfer and thereby enhanced the catalytic performance. This study provides a new strategy for designing CNT-modified catalysts for the efficient and stable removal of phenolic pollutants.