Metal-Organic Gels of Catechol-Based Ligands with Ni(II) Acetate for Dye Adsorption

Metal organic gels (MOGs) are a class of supramolecular complexes, which have attracted widespread interest because of the coupled advantages of inorganic and organic building blocks. A new compound terminated with catechol was synthesized. This new compound can be used to coordinate with Ni2+ to form MOGs. These MOGs show favorable viscoelasticity and wormhole-shaped porous structures, which were confirmed by transmission electron microscope and scanning electronic microscope images. Taking the benefits of porosity into account, the xerogel could serve as an adsorbent to adsorb dye molecules from the aqueous media. The experimental results indicate that xerogels possess good adsorption effect both on anionic and cationic dyes. Exhaustive research has been performed on the adsorption kinetics and isotherms, revealing that the adsorption process accords with the pseudo-second-order model and the Langmuir model.