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.

Abstract

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.