A bio-based metal–organic aerogel (MOA) adsorbent for capturing tetracycline from aqueous solution

The increasingly severe issue of antibiotic-induced pollution greatly stimulates the development of high-performance advanced adsorbents. In this contribution, a novel Fe-centered metal–organic aerogel (Fe-MOA) was synthesized through the use of bio-based ligand 2,5-furandicarboxylic acid (FDCA). Various characterization techniques including FT-IR, XPS, SEM, TEM, EDX and N2 adsorption–desorption analysis verified the successful preparation of the Fe-MOA with a hierarchically meso and macroporous network structure. The Fe-MOA was subsequently used as an adsorbent for the removal of tetracycline (TC) in aqueous solution. And the results suggested that the Fe-MOA exhibited an unprecedented adsorption capacity for TC with the record value of 1023 mg g−1. The adsorption equilibrium and isotherm data agreed well with the pseudo-second-order and Freundlich models, respectively. The mechanism investigations showed that the ultrahigh adsorption capability was synergistically driven by multiple affinities including electrostatic interaction, hydrogen bonding, surface complexation and π–π interactions between the conjugated groups in TC and the furan rings of the Fe-MOA. The recycling adsorption experiment results showed that the Fe-MOA retained 80% of the 1st-cycle adsorption capacity after being reused for 5 cycles, demonstrating the excellent reusability of Fe-MOA. Compared with other adsorbents, the ultrahigh TC adsorption capacity and excellent recycling performance make the Fe-MOA a favorable adsorbent candidate for TC pollution, highlighting the significant potential for solving practical TC-related pollution issues.