Construction of bifunctional active sites in metal-organic framework for effective albendazole capture

Developing efficient adsorbents for the capture of albendazole is of great significance but still faces challenges. Herein, an adsorbent (MIL-101(Cr)–SO₃H) with a dual-functional active site was synthesized. Benefiting from the abundant –SO₃H groups and unsaturated coordination Cr metal sites, the adsorbent exhibits excellent adsorption performance for albendazole. The maximum adsorption amount can reach 196.4 mg g⁻¹, higher compared to other reported adsorbents. The kinetic study reveals that saturation equilibrium is achieved within 500 min. The adsorption thermodynamics study indicates the adsorption process was spontaneous and endothermic. Experimental characterization and density functional theory calculation jointly demonstrate that coordination, electrostatic attraction, and π-π interactions play primary roles in albendazole adsorption. In addition, this adsorbent has outstanding chemical and thermal stability as well as good adsorption-desorption-regeneration cycle performance. Eventually, this work constructs an efficient adsorbent for the capture of albendazole.