Preparation of catalytic ceramic nanofiber membranes with MnFe dual-active sites enhancing catalytic ozonation of sulfamethoxazole

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Membrane-based catalytic ozonation has recently attracted significant attention for its simultaneous boosted contaminant degradation and separation. In this work, catalytic ceramic nanofiber membranes ((MnFe0.05)@CNM) with MnFe dual-active site are prepared by anchoring FeOx nanoparticles onto Mn@CNM via an impregnation and in-situ precipitation method. The (MnFe0.05)@CNM coupled with catalytic ozonation was applied to the degradation of sulfamethoxazole (SMX), achieving a removal rate of up to 99.2 %. The catalytic degradation of SMX is verified by reactive oxygen species (ROS) quenching and EPR detection experiments, which shows that the 1O2, ·OH and O2·- are involved. Furthermore, (MnFe0.05)@CNM demonstrates superior catalytic stability, redox properties, and an abundance of acidic sites, as are revealed by H2-TPR and NH3-TPD analysis. The boosted performance is attributed to the synergistic catalysis by Mn and Fe bimetals under nano-confinement effect of membrane pores through facilitated electron transfer between Mn2+, Mn3+, Mn4+, Fe2+, and Fe3+, and promoting the decomposition of ozone and the generation of ROS. The nano-confinement effect of (MnFe0.05)@CNM also reduces the mass transfer distance between ROS and SMX, promoting ROS to attack the SMX molecules. This study presents a novel approach to developing catalytic ceramic membranes for the enhanced degradation of emerging contaminants in water.