Heterogeneous nucleation and synthesis of carbon dots hybrid Zr-based MOFs for simultaneous recognition and effective removal of tetracycline

Discharged tetracycline (TC) seriously threatens human health and environmental safety. Herein, we developed a novel 3D flower-on-sheet structure of Zr-metal organic framework adsorbent with the assistant of N,S co-doped carbon dots as heterogeneous nucleation (UiO-67/NSC) for selective and effective removal of TC residue from contaminated water. Functional groups of UiO-67/NSC acts as a tentacle to identify TC molecules, and TC-adsorbed NSC can be separated easily by incorporating in UiO-67 structure. Hierarchical UiO-67/NSC exhibited excellent recognition performance with a wide sensitive range (0.08-20.0 mg/L) and low detection limit (0.063 mg/L) for TC. Particularly, vertically oriented 2D nanosheets in UiO-67/NSC alleviate the diffusion barrier and enhance mass transfer between adsorption sites and TC molecules, endowing it with an ability that can improve the TC adsorption capacity of parent UiO-67 to 427.35 mg/g. UiO-67/NSC with OD structure has no significant toxic effect on human cells (HepG2 and Caco-2), which demonstrate the prepared hybrid structure is safety in practical application. Our data indicate the great potential of UiO-67/NSC as an innocuous, bifunctional, smart adsorbent for the effective detection and removal of TC residues, and we not only provide a rational design of advanced metal organic framework-based hierarchical adsorbents, but also shed light on an available method to toxic antibiotic residue recognition and water remediation.