Study of the Dye Adsorption Kinetics ofMetal-OrganicFrameworks in Aqueous Media

Water can easily be contaminated by many dye molecules because of its high solubility with dense color. Dye-contaminated water requires purification via the adsorptive removal of dye molecules, employing various porous materials. To increase the removal efficiency and selectivity, demands for developing new metal-organic frameworks (MOFs) for dye removal continue to increase. Herein, we present a study on the dye-adsorption properties of MOFs based on their structures and pore sizes. The effects of dye molecule charge and size were also investigated. Three different MOFs (Universitetet i Oslo; UiO-66, UiO-67, Materials of Institute Lavoisier; MIL-100 [Fe]) and four dye molecules (Methylene Blue, Rhodamine B, Tropaeolin O, and Amaranth) were employed. The results suggest that the surface properties and framework structure of the MOFs affect dye adsorption capacity and kinetics, as characterized by UV-Vis spectroscopy and adsorption kinetics analysis. These results provide opportunities for the development of MOFs for dye removal from aqueous solution.