A facile strategy to increase the selectivity of heterogeneous Fenton oxidation is investigated. The increase was reached by increasing selective adsorption of heterogeneous Fenton catalyst to a target pollutant. The heterogeneous Fenton catalyst was prepared by a two-step process. First, zeolite particles were imprinted by the target pollutant, methylene blue (MB), in their aggregations, and second, iron ions were loaded on the zeolite aggregations to form the molecule imprinted Fe-zeolites (MI-FZ) Fenton catalyst. Its adsorption amount for MB reached as high as 44.6 mg g while the adsorption amount of un-imprinted Fe-zeolites (FZ) is only 15.6 mg g. Fenton removal efficiency of MI-FZ for MB was 87.7%, being 33.9% higher than that of FZ. The selective Fenton oxidation of MI-FZ for MB was further confirmed by its removal performance for the mixed MB and bisphenol A (BPA) in solution. The removal efficiency of MB was 44.7% while that of BPA was only 14.9%. This fact shows that molecular imprinting is suitable to prepare the Fe-zeolites (FZ)-based Fenton catalyst with high selectivity for removal of target pollutants, at least MB.

BACKGROUND The heterogeneous photo‐Fenton‐like process is emerging as a promising treatment of dye‐containing wastewater because of its economic feasibility and high efficiency. However, it is still required to develop photo‐Fenton‐like catalysts with highly selective degradation ability and reusability. RESULTS Inorganic‐framework molecularly imprinted Fe‐doped TiO2 composites (MIP/Fe–TiO2) were successfully prepared by the sol–gel method, with acid orange II as the template and TiO2 as the matrix material. The photo‐Fenton‐like catalysts were characterized using FESEM, EDS, BET, X‐ray diffraction, FT‐IR spectroscopy and UV–vis diffuse reflectance spectroscopy. These methods revealed the well‐crystallized anatase phase and good nanometer‐level particle sizes. The adsorption property and photo‐Fenton‐like activity of the catalysts were also studied in single and binary systems, respectively. CONCLUSIONS Compared with non‐imprinted Fe–TiO2 composites (NIP/Fe–TiO2), MIP/Fe–TiO2 showed higher adsorption capacity and selectivity toward the template molecule. In addition, it was found that the molecular recognition ability of MIP/Fe–TiO2 provided the catalysts with rapidly selective photo‐Fenton‐like degradation of low target pollutant levels (20 mg L−1) in the presence of high levels of interferential pollutant sodium dodecyl benzene sulfonate (100 mg L−1). Moreover, because of the stable physicochemical properties of the inorganic framework, the new photo‐Fenton‐like catalysts were resistant to photochemical attack and showed favorable reusability. © 2017 Society of Chemical Industry

A novel inorganic molecular imprinted polymer (MIP) was synthesized by adding Al(3+) to the Fe/SiO2 gel with Acid Orange II (AO II) as the template. The MIP was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption measurement. Compared with the non-imprinted polymer (NIP), the MIP enhanced the adsorption capacity of the target pollutants AO II. The selective adsorption capacity study indicated that the MIP adsorbed more AO II than the interferent Bisphenol A (BPA), which also has the structure of a benzene ring, thus proving the selective adsorption capacity of the MIP for template molecules AO II. In addition, the adsorption of AO II over MIP belonged to the Langmuir type and pseudo-second adsorption kinetics, and Dubinin-Radushkevich model indicates that the adsorption process of AO II over MIP and NIP are both given priority to chemical adsorption. The MIP reusability in performance was demonstrated in at least six repeated cycles.

In order to realize the selective oxidation of Fenton-like reaction, an inorganic molecularly imprinted Fe/Al/SiO