Comparison of adsorption properties for anionic dye by metal organic frameworks with different metal ions

Two dimensional MOFs materials with different metal ions were prepared through a facile and mild method at an ambient temperature and characterized to verify successful preparation of the materials. The MOFs materials were used to remove anionic dye alizarin yellow GG from aqueous solution in comparison with each other. Several parameters such as contact time, initial concentration, temperature and ionic strength affecting adsorption efficiency were systematically investigated. It was found that the adsorption capacity of the MOFs materials with zinc as linker for the dye was the highest, indicating type of metal ion greatly influence adsorption efficiency. It was surprising to find that effect of ionic strength on adsorption of the material with copper linker was promotive while that of the materials with zinc and nickel liners was inhibited which may be due to different chemical structures of the adsorbents. The dye loaded MOFs materials could be regenerated with simple method and the materials had superior stability and reusability during the five adsorption-desorption cycles. Furthermore, the MOFs materials could selectively enrich anionic dyes from contaminated effluents with cationic and anionic dyes. The MOFs materials prepared were efficient and potential adsorbents to remove anionic dyes from aqueous solution.