Optimizing Mg-Fe layered double hydroxide and efficient removal of methyl orange: screening, performance and mechanism

This study investigates the influence of key factors on the structure of prepared MgFe-LDH and their application for the removal of methyl orange (MO). The optimal synthesis were determined through Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and partition coefficient (PC) analysis to study the morphology, crystallinity, and physicochemical properties of the resulting materials. Under the conditions of Mg2+/Fe3+=4, pH=11, and aging temperature of 80℃, well-structured Mg4Fe-LDH-11-80℃ was successfully synthesized with a theoretical maximum adsorption capacity of 1688.22 mg/g for MO. The adsorption process follows the Redlich-Peterson and Avrami models, displaying a exothermic characteristic. The outstanding adsorption capability is likely attributed to the synergistic effects of electrostatic attraction, hydrogen bonding, complexation reactions, and ion exchange mechanisms. Furthermore, cost analysis and recycling experiments indicate that the prepared LDH material is cost-effective and suitable for multiple reuse cycles, making it a promising candidate for treating wastewater containing MO dyes.