Molecular modeling analyses for electronic properties of CNT/TiO₂ nanocomposites

Electronic properties of carbon nanotubes (CNTs) is enhanced with the help of metal oxides which in turn paves the way toward functionality of CNTs for many applications based on their electronic properties. Accordingly, density functional theory at B3LYP/3-21g** is utilized to model the decoration of CNTs and TiO₂. 7 molecules of TiO₂ are interacted with the CNT surface as adsorb state and complex. As a result of this decoration, a change in the Mulliken atomic charges of a carbon atom which is interacted with the metal is recorded, changing both the total dipole moment and HOMO/LUMO bandgap energy. The molecular electrostatic potential is localized toward the left side for the adsorb state then up and down for the complex state, which enhances the probability of forming hydrogen bonding with the surrounding. The change in the physical parameters of the surface promotes the decorated CNTs for many applications. For verification, CNTs is prepared with homemade CVD then decorated with TiO₂. XRD, TEM, and TGA confirmed that TiO₂ is located on the surface. Finally, the FTIR spectrum indicated that the studied model is suitable for the investigated system regarding both accuracy and computational time.