Fabrication of Core-Shell Amino-Modified UiO-66@UiO-67 for Catalytic Reduction and Adsorption of Cr (VI)

In this work, we synthesized core-shell NH2-UiO-66@UiO-67 via a solvothermal method to achieve controlled assembly of amino-modified UiO-66 and UiO-67 at micro and nano scale. NH2-UiO-66@UiO-67 exhibited notable visible light responsiveness and an increased specific surface area.In addition, it demonstrated outstanding performance in Cr(VI) removal, which can be attributed to the photocatalytic conversion of Cr(VI) into less toxic Cr(III), and the adjustable pores and large specific surface area facilitating Cr(III) adsorption. Notably, it exhibited a robust removal efficiency across a wide pH range of 2.0 to 10.0. Specifically, at pH = 2.0, the Cr(VI) solution with a concentration of 60 mg/L was completely removed within 140 min. The results show that the adsorption of core-shell NH2-UiO-66@UiO-67 meets the pseudo-second-order adsorption kinetics and has the ability of photocatalytic reduction of Cr (VI).