Advancements in wastewater Treatment: A computational analysis of adsorption characteristics of cationic dyes pollutants on amide Functionalized-MOF nanostructure MIL-53 (Al) surfaces

Abstract

Recently, research has become increasingly concerned with removing cationic synthetic dyes from the environment because of their aromatic rings and ecological stability, which causes serious health risks for humans and other living organisms. A dye-adsorption system is widely acknowledged as one of the most reliable and practical approaches to wastewater treatment, which is verified for its high effectiveness, low cost, simplicity, and adsorbent reusability. Interestingly, metal–organic frameworks (MOFs) have gained immense attention for their applications in removing dye pollutants from water. This study investigates the adsorption characteristics of well-known cationic dye pollutants, comprising Malachite green (MG), Rhodamine B (RHB), Methylene blue (MB), Toluidine Blue (TB), Gentian violet (GV), Neutral red (NR) on MOF nanostructures functionalized with amide groups using amide/MIL-53 (Al) in two acidic and basic environments via a multiscale computational approach, including Monte Carlo (MC), molecular dynamics (MD) simulations, quantum mechanics tools. The adsorption behaviour of amide/MIL-53 (Al) adsorbent was discussed regarding dye hydration, the role of the nature of the central metal, missing linker defects (MLDs) and missing cluster defects (MCDs) in its structure. The results showed that the amide/MIL 53 had a high adsorption capacity for the cationic dyes because of its robust interaction with positive charges on the dye molecules. The high adsorption potential was assigned to various interactions between the dyes and the adsorbent, including π-π stacking, van der Waals and electrostatic interactions, hydrogen bonding and other weak interactions. According to our findings, the benzene rings of RHB dyes interact more strongly with amide/MIL-53 (Al) surfaces owing to their higher π–π stack bonding energies and hydrogen bonding. The computational study also played a crucial role in predicting the cationic dye adsorption behaviour on the amide/MIL-53 (Al) nanostructure surfaces. The findings of this study have significant implications for the design and development of advanced adsorbent materials for removing cationic dye pollutants from contaminated water.