Tailoring Morphology and Fluorescence Properties of Zeolitic Imidazolate Frameworks via Carbon Dots

The assembly of carbon dots (CDs) and metal–organic frameworks (MOFs) into MOF@CDs composite materials is rapidly advancing in the field of nanoscience, driven by the potential to harness or enhance the advantages of both CDs and MOFs. However, the exploration of MOFs@CDs with controllable morphologies poses a considerable challenge. Herein, we present a universal synthetic strategy for zeolitic imidazolate frameworks (ZIFs)@CDs composite materials with tunable morphologies and solid-state fluorescence by modulating the surface structure of carbon dots and adjusting the reaction temperature. The assembly process of this strategy is mainly governed by the competitive coordination relationship between the surface functional groups of the carbon dots and the imidazole ligand and the zinc metal sources. Besides, the incorporation of ZIFs@CDs into sodium alginate (SA) to prepare a hydrogel (SA/ZIFs@CDs) effectively enabled the identification and adsorption of copper ions in which the 24-h adsorption capacity of SA/ZIF-L@CD₁ at an initial Cu²⁺ concentration of 500 ppm could reach 200.53 mg g^–1. Moreover, the hydrogels dressing after adsorption of Cu²⁺ could be used to resist the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work provides insights for further advancements in structural design and a deeper understanding of the assembly behavior of the MOFs.