First-Principles Insights on the Bonding Mechanism and Electronic Structure of SWCNT and Oxygenated-SWCNT Functionalized by Cellulose Biopolymer

Here, we report the bonding mechanism and electronic structure of single-walled carbon nanotube and oxygenated single-walled carbon nanotube functionalized by cellulose chain using first-principles density functional theory. Analysis of the optimized molecular configuration and charge redistribution of the nanohybrid indicates that the cellulose chain binds with the prototype single-walled carbon nanotube and oxygenated single-walled carbon nanotube via physisorption. The cellulose chain adsorption on the single-walled carbon nanotube preserved its electronic structure. On the other hand, the electronic structure of the oxygenated single-walled carbon nanotube and cellulose complex reveals that the electronic states of the cellulose tend to populate in the forbidden gap, thus, lowering the bandgap of the overall complex. The electronic structure of the complex can be considered as the superposition of its constituents in which no significant hybridization of the orbital characters is observable. The findings confirm that cellulose is indeed suitable for the non-covalent functionalization of single-walled carbon nanotubes and provide new insights into the electronic structure of the oxygenated single-walled carbon nanotube/cellulose complex.