Synthesis of highly stable nanoscale MIL-53 MOF and its application for the treatment of complex mixed dye solutions and real-time dye industry effluent

Abstract

In this work, solvothermal synthesis of MIL-53 (Al) was carried out using water and DMF as solvents, and at two different temperatures. The synthesized materials were characterized using standard analytical techniques and their properties were compared. Among the synthesized materials, MIL-53 (Al) synthesized at 150 °C using DMF as a solvent (MIL-53 (Al)150DMF) exhibited superior properties in terms of particle size, morphology, surface area, and pore size. The water and mechanical stability of MIL-53 (Al)150DMF was investigated. The material exhibited high stability in water and when subjected to external pressure between 0.1 and 1.5 GPa. The highly stable MIL-53 (Al)150DMF was employed for adsorptive removal of cationic, anionic, and mixed dye solutions. The adsorption capacities were 296.3 and 277 mg/g of individual cationic and anionic dyes, respectively. The material exhibited a remarkable capacity for the adsorptive removal of a highly complex mixed dye solution containing three cationic and three anionic dyes. A regeneration study depicted a reuse of the material without significant loss in the adsorption capacity. Further, the material was successfully tested for the adsorption of dye from a dye industry effluent.