Synthesis and characterization of metal organic framework using succinic acid ligand with cobalt and iron metals as methylene blue dye adsorbent

Abstract

Metal-organic Framework (MOF) as a porous material has a potency for an organic dye adsorbent due to its tunable pore size. It can be a good candidate for selective separation of organic dye waste because of its organic functionality, high thermal and stability. In this study, MOF based on cobalt (Co) and iron (Fe) cations with succinic acid ligand was utilized for Methylene Blue (MB) removal from aqueous solution. Co-MOF and Fe-MOF were synthesized using solvothermal method at 120 °C for 20 h and characterized by using infrared spectroscopy, X-Ray diffraction technique, thermogravimetric analyses, N2 adsorption-desorption isotherm, and scanning electron microscope. The adsorption of MB from aqueous solution by Co-MOF and Fe-MOF were carried out and their adsorption properties were investigated in various parameters such as pH solution, contact time, MOF loading. Moreover, their adsorption isotherm and reusable capacity were explored. As the results, the optimal adsorption was achieved at pH 9 for both MOFs, 5 mg of MOFs loading in 5 mL MB and 180 min for Co-MOF and 150 min for Fe-MOF. Both MOFs could be reused as a good adsorbent with the ratio of ethanol and H2O (70:30) as an eluent. This adsorption activity followed the Langmuir isotherm with the maximum adsorption capacity (Qm) of 3.9494 mg/g and 4.6685 mg/g for Co-MOF and Fe-MOF respectively.