In-situ growth of bimetallic FeCo-MOF on magnetic biochar for enhanced clearance of tetracycline and fruit preservation

Magnetic carbon materials as the fascinating scavenger have been used for the purification of antibiotic wastewater. However, a majority of the reported magnetic carbon adsorbents suffer from the poor adsorption capacity and costly preparation costs. Herein, we report an in-situ growth of bimetallic FeCo-metal organic frameworks (MOFs) on waste paper-derived CoFe2O4/porous carbon via a hydrothermal strategy for reinforced clearance of tetracycline. The adsorption properties and mechanisms were systematically explored. Results revealed that the adsorption isotherms obeyed the Langmuir model, and the pseudo-second-order kinetics model could be well used to describe the current adsorption behavior. The maximum Langmuir adsorption capacity of FeCo-MOF@CoFe2O4/porous carbon toward tetracycline was calculated as 909 mg g−1, which was significantly higher than that of other reported adsorbents. The ascendant capture property of the current adsorbent was presented under a wide pH range (5.0–12.0) and had excellent resistance to humic acid. In addition, the proposed coating method can also be applied to in-situ grow FeCo-MOF on biomass-derived magnetic porous carbon to enhance removal of tetracycline. Interestingly, the tetracycline adsorbed FeCo-MOF@CoFe2O4/porous carbon as a sustainable additive was further proved to be used for fruit preservation. Overall, this work provided a new research direction for in-situ architecture of magnetic carbon-based bimetallic MOF materials to treat antibiotic sewage and fruit preservation.