Constructing 3D hierarchical Fe@RGO supported nitrogen-doped carbon nanotubes to enhance peroxymonosulfate activation for achieving efficient antibiotic degradation

The application of persulfate-based advanced oxidation processes (AOPs) for the removal of emerging pollutants has garnered increasing interest in the field of water pollution control. However, the synthesis of catalysts that simultaneously exhibit stability and exceptional performance is currently facing enormous challenges. In this study, the in-situ growth of nitrogen-doped carbon nanotubes on stratified Fe@RGO substrate was employed to fabricate a novel three-dimensional (3D) composite material for efficient persulfate activation. The innovative design effectively integrated the superior porosity and high conductivity properties of carbon materials, resulting in a unique synergistic effect that facilitated rapid diffusion of reactants and efficient electron transfer. Meanwhile, the incorporation of nitrogen doping can effectively regulate the binding between metal particles and the substrate, thereby enhancing the stability of active sites. This catalyst not only removed SMX ultra-fast in 10   minutes through PMS activation, but also maintained 93% degradation after 5 cycles. A series of radical testing and trapping experiments revealed that the degradation mechanism is primarily dominated by a non-radical pathway. Additionally, electrochemical experiments confirmed that the Fe@RGO/NCNTs with its 3D interconnected layered structure facilitated direct electron transfer. This work demonstrates the broad application prospects of 3D interconnected iron-nitrogen co-doped carbon materials in organic pollution removal.