Good adsorption performance for both cationic and anionic dyes by a novel crosslinked tetrafluoroterephthalonitrile-tannic acid-chitosan polymer synthesized via one-pot reaction

In this work, tetrafluorophenonitrile was utilized to crosslink tannic acid and chitosan together to form a new crosslinked polymer (CSTTA), and then the Fe3O4 nanoparticles were prepared and immortalized on the CSTTA at the same time to obtain the Fe3O4/CSTTA composite. The structures of CSTTA polymer and Fe3O4/CSTTA composite were characterized by SEM, FTIR, TGA, 13CNMR, XPS, WAXD, N2 adsorption-desorption isotherm, VSM, and zeta potential measurement. The CSTTA could simultaneously adsorb the cationic methylene blue (MB) and anionic orange G (OG), and its adsorption behaviors for MB and OG conformed to the pseudo-secondorder kinetic model and the Langmuir isotherm model, which were spontaneous according to thermodynamic calculation. The CSTTA possessed not only high adsorption capacities for both MB and OG up to 1092.69 mg/g and 519.89 mg/g at 303 K under the optimal pH conditions of pH=10 and pH=1, respectively, but also the good reused ability. In addition, the Fe3O4/CSTTA composite could also absorb both MB and OG with good magnetically recollected ability to avoid secondary pollution.