Dual-purpose ferric chloride was successively used as
a catalyst
and iron source for ferric oxide to conveniently prepare a magnetic
Fe3O4/HCPBn‑glu polymer with
tetrabenzylglucose as the precursor. First, ferric chloride was employed
as a Friedel–Crafts reaction catalyst for the synthesis of
hyper-cross-linked HCPBn‑glu. Subsequently, the
ferric chloride was utilized as an iron source for the synthesis of
Fe3O4 magnetic nanoparticles by coprecipitation,
which anchored Fe3O4 nanoparticles onto the
HCPBn‑glu skeleton. A variety of modern analytical
techniques were used to characterize prepared Fe3O4/HCPBn‑glu. The effects of adsorbent amount,
contact time, and pH were studied, and this composite showed excellent
adsorption performance for 2,4-dinitrophenol (DNP), with a maximum
adsorption capacity of 83.3 mg/g and removal efficiency of 91.7%.
The adsorption of DNP is well fitted by the Freundlich model, indicating
multilayer adsorption. The adsorption kinetics obey a pseudo-second-order
kinetic model. In addition, Fe3O4/HCPBn‑glu can be reused for at least six cycles with an acceptable removal
efficiency, making it an economically valuable adsorbent. The adsorption
mechanism was also discussed, and hydrogen bond, hydrophobic, and
π–π interactions may be responsible for DNP adsorption.
Based on these results, Fe3O4/HCPBn‑glu can be utilized as an effective adsorbent for the removal of nitrophenols
from sewage.