An excellent adsorption performance of acesulfame and saccharin from water on porous carbon derived from zinc-based MOFs: The role of surface chemistry and hierarchical pore structure

Abstract

Due to the strong polarity and difficult in biodegradation, acesulfame (ACE) and saccharin (SAC) are difficult to treat effectively in water environment. Herein, a series of ACE and SAC adsorption were investigated by the zinc-based MOFs (ZIF-8, MAF-6, MOF-5 and Zn-MOF-74) derived porous carbons (MPCs). The porous carbon derived from MOF-5 (MPCs-M5) and Zn-MOF-74 (MPCs-M74) of zinc-based carboxylate MOFs exhibited large surface area (2774.7 m2/g and 2447.3 m2/g), high mesoporosity (94.57% and 95.66%) and equipotential point value (7.85 and 9.82). The pseudo-second-order kinetic model and Freundlich adsorption model were fitted well to explore adsorption on the MPCs-M5 and MPCs-M74, respectively. Moreover, the MPCs-M5 and MPCs-M74 showed notable adsorption capacity of ACE (96.4 mg/g and 88.6 mg/g) and SAC (117.3 mg/g and 113.4 mg/g), respectively, which were the highest value than the previous reports. Furthermore, the excellent adsorption performance of MPCs-M5 and MPCs-M74 were also contributed by multi-faceted synergy of electrostatic, H-bond, and π-π interactions. Therefore, the above two samples of the hierarchical porous carbon prepared by self-activating zinc-based carboxylate MOFs with high oxygen content are recommended as efficient adsorbents for artificial sweeteners adsorption from water environment.