Magnetic Field Assistant Method for Synthesizing Imprinted Photocatalytic Membrane with Highly Exposed ZnFe2O4@PoPD Heterojunction for Efficient Selective Degradation

Although the phase inversion method has been widely used for the preparation of the photocatalytic polymer membrane, the embedding of photocatalytic powder in the inside of the polymer membrane seriously blocks the active site and limits the photocatalytic efficiency. In this work, we demonstrate that using a magnetic photocatalyst to prepare the photocatalytic membrane can solve the above challenges with the help of magnetic field assistant method. Moreover, a ZnFe2O4@Poly(o-phenylenediamine) core-shell heterojunction (I-ZnFe2O4@PoPD) with imprinted layer is employed as the photocatalyst to prepare the highly exposed imprinted photocatalytic membrane (IM-ZnFe2O4@PoPD), which provides recognized site to selectively capture the specific pollutants and facilitate the charge transfer by formed built-in electric field between ZnFe2O4 and PoPD. In addition, the photodegradation efficiency of the imprinted molecule, such as tetracycline (TC), over the as-prepared IM-ZnFe2O4@PoPD membrane reaches to 75.76%. Inversely, the photodegradation efficiency of unimprinted molecules, like ciprofloxacin (CIP), is only 20.28% in the same condition. The selectivity coefficient of IM-ZnFe2O4@PoPD relative to UIM-ZnFe2O4@PoPD can reach 2.6. Briefly, our work throws light on the preparation of membranes with more exposed active sites and high photocatalytic selectivity.