Density Functional Theory analysis and molecular dynamic simulation to understand the mechanism of hazardous dyes adsorption onto cellulose in aqueous solution

Abstract

This work examines the use of cellulose in the elimination of anionic dye, indigo carmine and methyl red, from aqueous media. Theoretical analyses revealed that the examined compounds had several reactive sites that encouraged dyes to adhere to the cellulose surface, and molecular dynamics simulations demonstrated that this adsorption occurred flat-lying on the cellulose (200) surface. However, it has been discovered that the reactivity of individual molecules is limited in its ability to foretell the effectiveness and characteristics of compound adsorption on cellulose. The capacity to model dye adsorption on polymeric surfaces in the presence of a simulated aqueous solution is one of the key benefits of molecular dynamics modeling, and it can reveal valuable information regarding the selected molecules' adsorption configuration and its competitiveness. Both dyes exhibit high adsorption on the cellulose adsorbent, indicating that chemical bonds play a major role in the adsorption capacity of the dyes. The order of adsorption energy indicates a clear selective adsorption tendency. The radial distribution function analysis shows that both dyes are chemisorbed at the cellulose surface. Quantum and dynamic descriptors have validated the experimental results in the literature. This offers valuable insights into the adsorption mechanism of anionic dyes on cellulose.