MIL-101(Fe)@ceramic-monolith for arsenic removal in aqueous solutions

In this work, we present the preparation of a hybrid material constituted by a Metal-Organic Framework (type MIL-101(Fe)) and a natural clay ceramic monolith (NCCM), the materials were successfully assembled through an in-situ hydrothermal method. The composites were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N₂ adsorption-desorption isotherms at 77 K and CO₂ adsorption at 273 K; these techniques confirmed the obtaining of the hybrid material and, in addition, through studies before and after adsorption mechanisms involved were identified. Then, the As(V) adsorption capacity of the materials was evaluated using an aqueous arsenic solution; from which high adsorption capacities of up to 268 mg g^{- 1} and 61.5 mg g^{- 1}, respectively. In addition, kinetic and equilibrium studies of As(V) adsorption were carried out. Finally, the potential capacities of the hybrid material consisting of Al₂O₃, AlO₆-SiO₄ and Fe₃O₄ for the adsorption of H₃AsO₄, were studied through density functional theory calculations.