Precise Manipulation of Amino Groups in Zr-MOFs for Efficient Adsorption Performance

Abstract

Developing high-performance adsorbents for heavy metal (Cr (VI)) removal is essential for sustainable environments, but it is still challenging. Herein, a simple solvothermal method was proposed to fabricate Zr-MOFs (UiO-66), which was innovatively modified by amino groups to enhance the adsorption capacity of Cr (VI). The effects of the content of amino-functionalized ligands on the adsorption capacity and the influence of adsorbent content, solution pH, adsorption time, and adsorption temperature on the adsorption process were systematically investigated. Importantly, the pore structure and defect structure of UiO-66 can be finely regulated by adjusting the amino modification process. The adsorption process was fitted and analyzed using the kinetic model and the isotherm model. Impressively, the adsorption capacity of the amino-modified UiO-66 (UiO-66-NH2) was greatly improved. These findings indicate that the surface functional group modification of MOFs is a promising method for adjusting their structure and improving their adsorption capacity.