High-performance Removal of Tetracycline Enabled by Fe0 Nanoparticles Supported on Carbon@ZIF-8

Significant concerns have been raised over the removal of antibiotics, such as tetracyclines(TC) in aquatic environments. Herein, we synthesized a new type of heterogeneous catalyst by supporting Fe0 nanopartciles(FeNPs) onto carbon coated ZIF-8 (C@ZIF-8). The carbon layer formed by glucose was beneficial to maintain the morphology and porous structure of ZIF-8, which can also appropriately improve the hydrophobicity of ZIF-8 for enriching the TC. The as-prepared FeNPs-C@ZIF-8 catalyst featured an extreme large specific surface area(1122.16 m2/g), and the supported FeNPs with an average diameter of 6.13 nm exhibited a high dispersity on the supporting matrix of C@ZIF-8. For the removal of tetracycline, the large specific surface area of FeNPs-C@ZIF-8 allowed for an easy access of tetracycline to the FeNPs, while the highly dispersed FeNPs served as actived sites for the efficient degradation of tetracycline. A synergistic effect between adsorption and catalytic degradation of FeNPs(5%, mass fraction)-C@ZIF-8 was proven to be responsible for the high-performance removal of tetracycline with the removal efficiency high up to 93.02% at pH 5, 25 °C. The FeNPs-C@ZIF-8 was capable of recycling after activation with supplementary Fe0, which still maintained a high removal efficiency of 75.52% in the 5th cycle within 20 min.