Microwave-enhanced synthesis of magnetic porous covalent triazine-based framework composites for fast separation of organic dye from aqueous solution

A novel type of magnetic porous carbonaceous polymeric material, CTF/Fe2O3 composite (CTF = covalent triazine-based framework), has been synthesized by a facile microwave-enhanced high-temperature ionothermal method. By selecting ZnCl2 as a reaction medium and the Lewis acid catalyst, and choosing FeCl3·6H2O as an iron oxide precursor, a series of CTF/Fe2O3 composites with different γ-Fe2O3 contents has been prepared in 60 min. The resulting samples were characterized by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibration sample magnetometer (VSM), and N2 sorption-desorption isotherms. The obtained CTF/Fe2O3 composites exhibit high surface areas (930-1149 m2 g−1), and their saturation magnetizations at 300 K vary from 1.1 to 5.9 emu g−1, depending respectively on different Fe2O3 contents (6.43-12.43 wt%) in the CTF/Fe2O3 composites. The CTF/Fe2O3 composites were applied to remove organic dye from aqueous solution by selecting methyl orange as a model molecule, and both high adsorption capacity (291 mg g−1, corresponding to 0.889 mmol g−1) and fast adsorption kinetics (kads = 4.31 m2 mg−1 min−1) were observed.