Construction of dual-imprinted UiO-66 s for highly efficient and synergistic Co-adsorption of diclofenac sodium and Cu(II)

Introducing imprinted pores into microporous UiO-66 to regulate the pore structure and surface properties can enhance adsorption properties. In-situ dual-imprinting of copper ion (Cu(II)) and 2,4-Dihydroxybenzoic acid (DBA) was used to construct adsorption sites for Cu(II) and diclofenac sodium (DCF) in the dual-imprinted UiO66 (UiO(Zr/Cu)-DBA). Characterization results revealed UiO(Zr/Cu)-DBA has a higher mesoporous volume, varied -COOH and -OH groups, and unsaturated Zr metal sites. Based on these sites, Cu(II) and DCF could be adsorbed by coordination with the unsaturated Zr metal sites and H-bonding with -COOH, -OH groups. Therefore, the adsorption capacities of UiO(Zr/Cu)-DBA for single Cu(II) and DCF rose to 66 and 475 mg/g, which were 2.3 and 4.5 times the original UiO-66 capacities, respectively. Meanwhile, the adsorbed Cu(II) and DCF may be utilized as bridge molecules to adsorb more Cu(II) and DCF. As a consequence, the adsorption capacities of UiO(Zr/Cu)-DBA for Cu(II) and DCF increased to 164 and 757 mg/g, respectively, which was 3.2 and 1.6 times higher in the mixed system than in the one-component system. These properties demonstrate the potential application of UiO(Zr/Cu)-DBA to remove Cu(II) and DCF concurrently, as well as a new guideline for removing non-steroidal anti-inflammatory drugs (NSAIDs) and heavy metals (HMs) from aquatic environments.

Automated summary

Introducing imprinted pores into microporous UiO-66 to regulate pore structure and surface properties enhances adsorption properties. In this study, dual-imprinting of copper ion (Cu(II)) and 2,4-Dihydroxybenzoic acid (DBA) was used to construct adsorption sites, resulting in higher adsorption capacities for Cu(II) and diclofenac sodium (DCF). The adsorbed Cu(II) and DCF can also act as bridge molecules to adsorb more Cu(II) and DCF, leading to increased adsorption capacities in the mixed system. These findings demonstrate the potential application of UiO(Zr/Cu)-DBA for concurrent removal of Cu(II) and DCF, as well as for removing NSAIDs and HMs from aquatic environments.