Target recognition and preferential degradation of toxic chemical groups by innovative group-imprinted photocatalyst with footprint cavity

Abstract

Target recognition and preferential degradation of toxic chemical groups remain critical challenges in photocatalytic degradation of organic contaminant. In this study, the concept of group-imprinting was first proposed, and group-imprinted copolymers of aniline and pyrrole were grafted from the surface of magnetic CuFeO2@MnO2 nanocomposites (MIP-CuFeO2@MnO2) using acrylamide as dummy templates for imprinting the amide group of tetracycline for the first attempt, and the molar ratios of dummy template molecule to functional monomer was optimized. The magnetic MIP-CuFeO2@MnO2 showed high adsorption capacity and good recognition for tetracycline. In mixture solution of tetracycline and ibuprofen, the distribution coefficient (kd) value of MIP-CuFeO2@MnO2 for tetracycline was 0.308 L/g, which is 6.86 times more than for ibuprofen (only 0.045 L/g). The selection factor (α) of MIP-CuFeO2@MnO2 is about 3.2 times that of non-imprinted counterpart, indicating that the imprinting cavities in copolymer layer which match with the amide groups of tetracycline can selectively recognize and adsorb tetracycline. More importantly, MIP-CuFeO2@MnO2 exhibited preferential degradation performance for amide groups, which was confirmed by the intermediates and degradation pathway. The E. coli growth suggests effective toxicity reduction of tetracycline due to the preferential degradation of amide groups by photocatalysis of MIP-CuFeO2@MnO2.