Targeted degradation of emerging pollutants based on specific recognition and ROS confinement effects of molecularly imprinted cavities

Traditional advanced oxidation processes (AOPs) have limitations in degrading trace emerging pollutants, including short reactive oxygen species (ROS) lifetimes, limited mass transfer distances, and susceptibility to interference from complex matrices, resulting in low ROS utilization. This study prepared a surface molecularly imprinted catalyst (MIP@MAC) that combines the targeted recognition of pollutants by molecularly imprinted polymers (MIP) with the highly efficient activation of peroxymonosulfate (PMS) by modified activated carbon (MAC). MIP@MAC improves the contact efficiency between ROS and SMX by leveraging the targeted recognition ability of the imprinted layer for sulfamethoxazole (SMX) and the confinement effect of the imprinted cavity on the generated ROS, effectively solving the problem of low ROS utilization. Performance evaluation showed that the MIP@MAC/PMS system exhibited excellent targeted removal capability for SMX, with removal rates 13.1 times that of competing pollutants carbamazepine and 3.81 times that of ofloxacin. Furthermore, the MIP@MAC/PMS system demonstrated good size exclusion effect and anti-interference properties against large molecular humic acids during the targeted removal of SMX. Importantly, the study revealed that the nano-confinement effect of the imprinted cavity is the key to improving targeting performance: it not only increases the local concentration of SMX through “targeted enrichment” and shortens the mass transfer distance between SMX and ROS, but also promotes PMS activation by generating “confinement energy”, thereby systematically addressing the problem of low ROS utilization. Furthermore, the system is effective over a wide pH range (3–9) and exhibits good reusability and environmental safety. This study provides a reference for improving the efficiency of AOPs and the targeted removal of trace emerging pollutants.