Single cobalt atoms anchored on Ti3C2Tx with dual reaction sites for efficient adsorption-degradation of antibiotic resistance genes

The assimilation of antibiotic resistance genes (ARGs) by pathogenic bacteria poses a severe threat to public health. Here, we reported a dual- reaction-site-modified CoSA/ Ti3C2Tx (single cobalt atoms immobilized on Ti3C2Tx MXene) for effectively deac-tivating extracellular ARGs via peroxymonosulfate (PMS) activation. The enhanced removal of ARGs was attributed to the synergistic effect of adsorption (Ti sites) and degradation (Co-O3 sites). The Ti sites on CoSA/Ti3C2Tx nanosheets bound with PO43- on the phosphate skeletons of ARGs via Ti-O-P coordination interactions, achieving excellent adsorption capacity (10.21 x 1010 copies mg-1) for tetA, and the Co-O3 sites activated PMS into surface -bond hydroxyl radicals (& BULL;OHsurface), which can quickly attack the backbones and bases of the adsorbed ARGs, resulting in the efficient in situ degra-dation of ARGs into inactive small molecular organics and NO3. This dual-reaction-site Fenton- like system exhibited ultrahigh extracellular ARG degradation rate (k > 0.9 min-1) and showed the potential for practical wastewater treatment in a membrane filtra-tion process, which provided insights for extracellular ARG removal via catalysts design.