Assessment of the robustness of MIL-88A in an aqueous solution: Experimental and DFT investigations

Abstract

The stability of metal organic frameworks (MOFs) in a water-rich environment is a topic of significant importance, especially for adsorption and water purification applications. MIL-88A containing iron ions and fumaric acid ligands, was synthesized through a water-based viable strategy. The robustness of MIL-88A in aqueous solutions was studied experimentally, through evaluating the chemical, thermal, and hydrolytic stability of this compound by varying the conditions and properties of aqueous solutions. Different characterization techniques were employed to explore the features of the synthesized MIL-88A such as XRD, SEM, FTIR, TGA, UV–vis DRS, zeta potential, and MP-AES measurements. The electronic structure was studied on a model nanocrystal with density functional theory (DFT) calculations. The MIL-88A structure was drastically affected in basic medium as confirmed by the characterization techniques used. MIL-88A became completely amorphous upon exposure to boiling water. The hydrolytic stability results showed that MIL-88A loses gradually its structural integrity in each water cycle.