Role of cellulose like materials in heavy metals coordination

Abstract This study investigates the coordination mechanism and electronic properties of cellulose and cellulose-like materials, such as dried banana peel, in the removal of heavy metals (Cadmium and Copper) from aqueous solutions. Using density functional theory (DFT) at the B3LYP/LANL2DZ level, model molecules of hydrated Cd and Cu interacting with glucose-based models representing local cellulose coordination sites (Charge 0; Singlet for Cd, Doublet for Cu) were analyzed. The results indicate that the coordination of metal ions significantly enhances the total dipole moment (TDM) and reduces the HOMO-LUMO energy gap (∆E), transforming cellulose from a stable, and low-polarity material into a highly polar and chemically active species. Specifically, the 2Cel.Cu.2H 2 O complex exhibited the highest chemical reactivity, while 2Cel.Cd.2H 2 O showed the most significant structural polarization. However, the dispersion analysis indicated that the 2Cel.Cu.2H 2 O complex demonstrated the greatest structural polarization, so we conducted an experimental analysis. Topological investigations, including Quantum Theory of Atoms in Molecules (QTAIM) and Non-Covalent Interaction (NCI) analyses, confirmed the formation of closed-shell, ionic coordination interactions and stabilizing intramolecular hydrogen bonds. Experimental validation through FTIR and Flame Atomic Absorption Spectroscopy (FAAS) demonstrated that both materials effectively reduced heavy metal concentrations, with dried banana peel showing superior performance for Cadmium removal. These findings suggest that metal complexation tunes the physicochemical properties of cellulose, enhancing its efficiency for environmental applications like wastewater treatment.