N-doped regular octahedron MOF-199 derived porous carbon for ultra-efficient adsorption of oxytetracycline

In this work, novel porous carbon nanocomposites derived from the carbonization of polyvinyl pyrrolidone doped (PVP-doped) MOF-199 at different temperatures were successfully prepared for adsorptive removal of oxytetracycline in aqueous solution. The physic-chemical properties of the as-prepared materials were characterized. Further researches showed that the product of PVP-doped MOF-199 with the pyrolysis temperature 300 °C had the best adsorption effect on oxytetracycline. The effects of calcination temperature, pH, coexisting inorganic ions and organic macromolecules on the adsorption were investigated. The interactions have been studied based on response surface model among four variables including pH, Ca2+ strength, humic acid and OTC concentration. Fitting results of kinetics and isotherms showed that the adsorption conformed to pseudo-second-order model and Langmuir model with the maximum adsorption capacity 1280.422 mg∙g−1, which was much higher than that in reported literatures. The combined actions of electrostatic force, pore adsorption, metal–organic complexation, hydrogen bonding and π-π interaction/stacking took the important roles in adsorption mechanisms. Thus, the porous carbon can be considered as bight application prospect in oxytetracycline removal.