Magnesium oxide nanomaterials for effective adsorption of congo red dye and fluoride ions from aqueous solutions

Abstract

This study investigates the synthesis of nanostructured magnesium oxide (MgO) using the auto-combustion method with urea (MgO-U), glycine (MgO-G), and citric acid (MgO-C) as fuels, followed by subsequent calcination. The selection of fuel plays a crucial role in determining the morphology of the nanostructures. X-ray diffraction (XRD) analysis confirms that the samples exhibit a well-crystallized structure with the desired phase and are free of impurities. Field emission scanning electron microscopy (FESEM) shows that MgO-U nanoparticles have diameters ranging from 10 to 20 nm, MgO-C nanoparticles from 60 to 80 nm, and MgO-G nanoparticles from 80 to 100 nm. These MgO nanomaterials are specifically engineered for adsorption applications, aimed at removing toxic organic dyes and fluoride ions from aqueous solutions. Results demonstrate that MgO-G nanoparticles exhibit superior adsorption activity compared to MgO-U and MgO-C nanoparticles, with maximum uptake capacities of 1429 and 14 mg/g, respectively. The adsorption processes adhere to second-order kinetic model. These findings highlight the potential application of the synthesized MgO nanoparticles for mitigating water pollution by adsorbing pollutants from aqueous media.

Keywords

• Magnesium oxide
• Nanomaterials
• Adsorption
• Congo red dye
• Fluoride ion