High-capacity NCNT-encapsulated metal NP catalysts on carbonised loofah with dual-reaction centres over C–M bond bridges for Fenton-like degradation of antibiotics

The intensification of electron transport between the dual-reaction centres in Fenton-like catalyst is demonstrated through the incorporation of carbon-metal (C–M) bond bridges. Herein, nitrogen-doped carbon nanotube-encapsulated Fe3C (Fe3C@NCNT) with dual-reaction centres over short C–Fe bond was constructed through DFT calculation, and accordingly a series of NCNTs-encapsulated Fe/Fe3C, Co, and Mo2C nanoparticles on carbonised loofah were developed by dynamic thermal impregnation and subsequent pyrolysis process. The resultant catalysts displayed satisfactory degradation properties of antibiotics, in which Fe/Fe3C@NCNTs-CL-800 achieved norfloxacin (NOR) removal efficiency of 93.8% in 90 min under neutral pH, and presented excellent cycle stability in NOR removal as well as universality in various antibiotic degradation systems. The remarkable degradation performance of heterogeneous Fenton-like catalysts was attributed to enhancing electron transport to electron-rich M centres over short C–M bond bridges. This study will open a new perspective on the rational design of catalysts for Fenton-like degradation.