Polyoxometalate supported on a magnetic Fe3O4/MIL-88A rod-like nanocomposite as an adsorbent for the removal of ciprofloxacin,tetracycline and cationic organic dyes from aqueous solutions

In this work, a magnetic H₃PW₁₂O₄₀/Fe₃O₄/MIL-88A (Fe) rod-like nanocomposite as a stable and effective ternary adsorbent was fabricated by the hydrothermal method and utilized for the removal of ciprofloxacin (CIP), tetracycline (TC) and organic dyes from aqueous solution. Characterization of the magnetic nanocomposite was accomplished by FT-IR, XRD, Raman spectroscopy, SEM, EDX, TEM, VSM, BET specific surface area and zeta potential analyses. The influencing factors on the adsorption potency of the H₃PW₁₂O₄₀/Fe₃O₄/MIL-88A (Fe) rod-like nanocomposite including initial dye concentration, temperature and adsorbent dose were studied. The maximum adsorption capacities of H₃PW₁₂O₄₀/Fe₃O₄/MIL-88A (Fe) for TC and CIP were 370.37 mg g⁻¹ and 333.33 mg g⁻¹ at 25 °C, respectively. In addition, the H₃PW₁₂O₄₀/Fe₃O₄/MIL-88A (Fe) adsorbent had high regeneration and reusability capacity after four cycles. In addition, the adsorbent was recovered through magnetic decantation and reused for three consecutive cycles without a considerable reduction in its performance. The adsorption mechanism was mainly ascribed to electrostatic and π–π interactions. According to these results, H₃PW₁₂O₄₀/Fe₃O₄/MIL-88A (Fe) can act as a reusable effective adsorbent for the fast elimination of tetracycline (TC), ciprofloxacin (CIP) and cationic dyes from aqueous solutions.

A magnetic Fe₃O₄/MIL-88A Fe rod-like nanocomposite containing H₃PW₁₂O₄₀ was fabricated and applied as a new magnetically recoverable ternary adsorbent to remove antibiotics and dyes from aqueous solutions.