Magnetic porous carbons derived from metal-organic frameworks for effective adsorption of tetracycline

Recovery of adsorbent from solid-liquid adsorption system is important for the application of adsorption technique. Due to high efficiency and low cost, separation induced by external magnetic field has attracted large attentions. In this work, we prepared a series of cobalt-doped magnetic porous carbons (Co-PC) via using Co-benzimidazole (Co-PhIm) as the precursor. In the green synthesis of Co-PhIm, water was used to partly substitute the organic solvent that was applied in previous reports. Interestingly, upon the addition of water, the porosity was boosted and the magnetism was not weakened obviously. Among the prepared porous carbons, the optimized Co-PC-C exhibited a large adsorption capacity (998.3 ​mg ​g−1) for tetracycline (TC) and rapid equilibrium time (30 ​min) at low concentrations. Co-existing ions had almost ignorable interferences and the optimized pH was found near the neutral environment. Furthermore, this material can be well regenerated through a simple elution method. Therefore, our work provides an effective adsorbent for TC antibiotic and proposes a guideline to enhance the porosity of adsorbent. The Co-PhIm precursor was carbonized to magnetic porous carbon for effective adsorption of tetracycline. [Display omitted] •Water was used to partly substitute the organic solvent to prepare MOFs.•Magnetic porous carbons were obtained after a carbonization process.•The porous carbons exhibit large adsorption capacity and rapid kinetics for TC.•π-π stacking interaction contributes to the adsorption of TC.