Preparation of Fe-MIL(100)-encapsulated magnetic g-CN for adsorption of PPCPs from aqueous solution.

In the present work, the Fe-MIL(100) was encapsulated on the outer surface of magnetic g-CN through a simple method to synthesize a novel adsorbent. The as-prepared g-CN/MnFeO/Fe-MIL(100) was characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET specific surface area (BET), vibrating sample magnetometry (VSM), and plasma emission spectrometry (PES). The g-CN/MnFeO/Fe-MIL(100) possessed rough surface, large surface area (303.68 m/g), mesoporous structure and magnetic properties, which exhibited excellent adsorption performance for ciprofloxacin (CIP), oxytetracycline (OTC) and indomethacin (IDM) with the maximum adsorption capacities reaching up to 45.51, 64.34 and 103.91 mg/g, respectively. The adsorption processes of all three PPCPs could be described by different kinds of isotherms and kinetic models. Additionally, the adsorption capacity of the resulting adsorbent could maintain 73.43% of the first adsorption capacity even after ten cycles. Finally, the possible adsorption mechanisms of g-CN/MnFeO/Fe-MIL(100) for CIP/OTC/IDM were proposed. Thus, g-CN/MnFeO/Fe-MIL(100) possessed excellent features of high adsorption capacity, fast removal rate, easy synthesis, salt resistance and magnetic separation, which showed great potential application to be used as an effective adsorbent for adsorptive removal of PPCPs in wastewater.