Room-temperature synthesis of Fe/Cu-BTC for effective removal of tetracycline antibiotic from aquatic environments

Antibiotic adsorbents are getting significant attention due to the hazards posed by the accumulation of tetracycline antibiotics in water, which can adversely impact human and environmental health. Bimetallic organic frameworks (BMOFs) exhibit considerable potential in adsorption owing to their dense pore structures and synergistic effects. However, synthesizing efficient, low-cost, and easy-to-prepare BMOFs faces several challenges. Here, we describe the practical synthesis of a series of Fe/Cu-bimetallic organic frameworks (Fe/CuMOFs) using simple room-temperature aqueous solvent methods. The pore size structure of Fe/Cu-MOFs is determined by the Fe/Cu ratio employed in the synthesis process. Remarkably, when the Fe/Cu molar ratio was 1:2, the void ratio of Fe/Cu-MOFs increased to 0.7326 cm3/g, with a predominant mesoporous structure, and the maximum tetracycline (TC) adsorption capacity exhibited by Fe/Cu-BTC-1/2 was reported at a Q max of 1130.23 mg/g. The adsorption kinetics followed the quasi-second-order kinetic model, and the adsorption isotherms were consistent. The Fe/Cu-BTC-1/2 was effective throughout a wide pH range (6.0-10.0), exhibiting resilience against ionic interference and enabling recycling. The predominant mechanisms of TC adsorption by Fe/Cu-BTC-1/2 include coordination, vacancy filling, and it-it stacking. Thus, our research provides an excellent adsorbent for TC antibiotics and novel insights into the simple synthesis of BMOFs and their application in environmental remediation.