The Effects of Zn Doping on the Interaction of a Single Walled Carbon Nanotube with Penicillamine Drug: A DFT Study

At the present work, we report the interaction of the penicillamine (PCA) molecule adsorbed on the pure and Zn-doped single-walled carbon nanotubes (SWCNTs) using density functional theory calculations. We conclude that the interaction of PCA on the outer surface of Zn-doped SWCNT is due to chemisorption, while its interaction with the pure SWCNT is physisorption in nature. It is undrestood that the electronic and optical structure of the Zn-doped SWCNT is more sensitive to the presence of PCA in comparison with the pure SWCNT. The Mulliken population charge analysis and the density of states analyses represent that the nature of PCA adsorption on the applied Zn-doped SWCNT is electrostatic rather than covalent.