Interactions of iron-oxide filled carbon nanotubes with gas molecules

Abstract

This work presents a study on iron-oxide filled carbon nanotubes (CNTs) and their interaction with the surrounding atmosphere. Theoretical and experimental methods were employed to determine the interaction mechanism between the CNTs and some gases, such as O₂ and N₂. The electrical behavior of these CNTs under different atmospheric conditions was studied through resistance measurements, and for comparison, similar studies were conducted on non-filled carbon nanotubes. The iron-oxide filled CNTs were found to be more sensitive to the presence of O₂ than the non-filled carbon nanotubes. This behavior was confirmed by the first-principles simulations based on density functional theory with local spin density approximations for CNTs filled with hematite and magnetite iron-oxides. The theoretical study on the interactions of iron-oxide filled CNTs with gas molecules demonstrated a physisorption regime between the nanotube and the surrounding atmosphere, resulting in modifications of the electronic properties of this material.