Dye adsorption selectivity in pristine and aluminum-doped MCM-41 mesoporous silica: A density functional theory investigation
5
Issued Date
2025-09-01
Resource Type
ISSN
02775387
Scopus ID
2-s2.0-105008932203
Journal Title
Polyhedron
Volume
279
Rights Holder(s)
SCOPUS
Bibliographic Citation
Polyhedron Vol.279 (2025)
Suggested Citation
Singhanatkaisi N., Sirihengcharoen T., Janyodha T., Polnarai P., Linthong K., Tantirungrotechai J., Tantirungrotechai Y. Dye adsorption selectivity in pristine and aluminum-doped MCM-41 mesoporous silica: A density functional theory investigation. Polyhedron Vol.279 (2025). doi:10.1016/j.poly.2025.117651 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/111009
Title
Dye adsorption selectivity in pristine and aluminum-doped MCM-41 mesoporous silica: A density functional theory investigation
Author's Affiliation
Corresponding Author(s)
Other Contributor(s)
Abstract
The adsorption behaviors of cationic (methylene blue), neutral (neutral red), and anionic (methyl orange) dyes on pristine MCM-41 and aluminum-doped MCM-41 (Al-MCM-41) mesoporous silica represented as surface slab cluster model were investigated using ONIOM2(revPBE-D4/def2-SVP:GFN-FF) geometry optimizations and CPCM-revPBE-D4/def2-TZVP energy calculations. This study aims to elucidate molecular-level interactions and the impact of aluminum doping on dye adsorption selectivity. Methyl orange exhibited the strongest average adsorption energy on both MCM-41 (−42.17 ± 8.28 kcal/mol) and Al-MCM-41 (−38.49 ± 4.76 kcal/mol), likely due to multiple hydrogen bonds and reduced steric hindrance arising from its molecular shape and orientation. An independent t-test analysis was carried out to assess the statistically significant changes in the average adsorption energy upon doping. Aluminum substitution enhanced the averaged adsorption energy of cationic methylene blue (from −20.08 ± 6.24 to −23.31 ± 5.45 kcal/mol), while reducing that of anionic methyl orange. The adsorption of the neutral red dye remained statistically unchanged. These findings suggest that aluminum doping of MCM-41 can selectively enhance cationic dye adsorption from aqueous solutions, primarily through modified electrostatic interactions at the surface.