MOFs self-assembled molecularly imprinted membranes with photoinduced regeneration ability for long-lasting selective separation

Abstract

Molecularly imprinted membranes (MIMs) are promising in water treatment because of its predetermined selectivity, but the limitations of trade-off relationship between permeability and selectivity, as well as membrane failure hinder their wider applications. Herein, we report construction of MOFs self-assembled molecularly imprinted membranes (SA-MIMs) with photoinduced regeneration ability by visible light driven loading strategy for long-lasting selective separation of ciprofloxacin (CF). The visible light driven loading design leverages on the UiO-66-NH2 as visible light absorption medium to generate reactive oxygen species (ROS) to promote dopamine polymerization, which in turn facilitates the loading of the MOFs on the substrate membranes under mild conditions. The CF imprinted polymers layer was synthesized in water via reverse atom transfer radical polymerization (RATRP) that imparted the specific recognition ability and excellent water compatibility for the SA-MIMs. As a result, the prepared SA-MIMs display enhanced rebinding selectivity and permselectivity (αCF/PM = 4.02 and αCF/LF = 3.23) and permselectivity (βCF/PM = 3.44 and βCF/LF = 3.51) for target molecules. More importantly, based on the good photocatalytic activity of UiO-66-NH2, the target molecules adsorbed on the specific binding sites can be degraded and removed, thereby achieving photoinduced rapidly regeneration. The impressive long lasting selective separation performance of SA-MIMs in the regeneration assisted continuous separation process indicate that the potential in practical application.